Flat panel detector positioning method, system and device and medium

Abstract

The invention provides a flat panel detector positioning method, system and device and a medium, and the method comprises the following steps: obtaining a positioning image sequence and a magnetic field information sequence, which are collected based on a time sequence, of a flat panel detector in a target environment; extracting image coordinates of the flat panel detector in each positioning image; converting each image coordinate into a local space coordinate to obtain a local space position of the flat panel detector at each moving moment; matching each local spatial position with each piece of magnetic field information to obtain magnetic field information of the flat panel detector at each local spatial position as magnetic field distribution in the target environment; acquiring current magnetic field information of the flat panel detector; and determining the current position of the flat panel detector based on the magnetic field distribution and the current magnetic field information. According to the flat panel detector positioning method, system and device and the medium, high-accuracy positioning of the flat panel detector can be realized when low-frequency magnetic field distribution in the environment changes, and the positioning accuracy of the flat panel detector is greatly improved.

Description

Technical Field

[0001] The present application belongs to the field of positioning technology, and in particular, relates to a method, system, device and medium for positioning a flat panel detector. Background Art

[0002] Flat-panel detectors are one of the core components in digital X-ray imaging systems. They have high sensitivity and can obtain clear images at a lower radiation dose, thereby reducing radiation exposure to patients. They are widely used in various imaging examinations such as fluoroscopy, angiography, and CT.

[0003] During the use of the flat panel detector, it is necessary to position the flat panel detector to control the position of the flat panel detector relative to the X-ray source, so that the radiation dose distribution of the X-ray on the flat panel detector is more accurate, and the radiation dose received by the flat panel detector is avoided to be insufficient or excessive due to position deviation. At present, since the low-frequency magnetic field is not affected by the human body, the existing technology usually uses the low-frequency magnetic field to position the flat panel detector, and obtains the low-frequency magnetic field information at the location of the flat panel detector, and combines the low-frequency magnetic field distribution pre-determined in the space to obtain the current position of the flat panel detector, so as to realize the positioning of the flat panel detector. The existing flat panel detector positioning method usually pre-calibrates the magnetic field distribution in the space manually, and uniformly applies the manually calibrated magnetic field distribution to the subsequent positioning of the flat panel detector. Since the low-frequency magnetic field is easily disturbed by the metal materials in the surrounding environment, when the distribution of the metal materials in the space changes, it will cause the current low-frequency magnetic field distribution in the space to change, that is, the low-frequency magnetic field information at the current location of the flat panel detector is different from the low-frequency magnetic field information pre-determined manually. Therefore, there is a large deviation between the flat panel detector position obtained by the existing flat panel detector positioning method and the actual flat panel detector position, and the positioning accuracy of the flat panel detector is limited.

[0004] Based on this, how to reduce the impact of environmental changes on the positioning accuracy of the flat-panel detector and achieve high-accuracy positioning of the flat-panel detector is an important issue that needs to be solved urgently. Summary of the invention

[0005] In view of the above-mentioned shortcomings of the prior art, the purpose of the present application is to provide a flat panel detector positioning method for solving the problem that the current flat panel detector positioning method cannot accurately position the flat panel detector after the surrounding environment changes.

[0006] To achieve the above object and other related objects, the present invention provides a flat panel detector positioning method, comprising the following steps:

[0007] Acquire a positioning image sequence and a magnetic field information sequence based on time-sequential acquisition of the flat panel detector in the target environment; the positioning image sequence includes: each positioning image containing the flat panel detector acquired in real time during the movement of the flat panel detector; the magnetic field information sequence includes: magnetic field information of the flat panel detector at each moving position acquired in real time during the movement of the flat panel detector;

[0008] Extracting the image coordinates of the flat panel detector in each of the positioning images; converting each of the image coordinates into a local space coordinate to obtain the local space position of the flat panel detector at each moving moment;

[0009] Matching each of the spatial positions with each of the magnetic field information in a one-to-one correspondence, respectively, to obtain the magnetic field information at each position of the flat panel detector as the magnetic field distribution in the target environment;

[0010] Acquire current magnetic field information of the flat panel detector; determine the current position of the flat panel detector based on the magnetic field distribution and the current magnetic field information;

[0011] The local space coordinates are coordinates of the flat panel detector in a pre-constructed local space coordinate system; in the local space coordinate system, the relative positions between the devices used to position the flat panel detector remain unchanged.

[0012] In one embodiment of the present invention, the method for acquiring the positioning image sequence and the magnetic field information sequence includes:

[0013] During the movement of the flat panel detector, photographing the flat panel detector in real time, and sensing the magnetic field of the flat panel detector at each moving position in real time;

[0014] A positioning image of the flat panel detector at each moving moment is obtained as the positioning image sequence; and magnetic field information of the flat panel detector at each moving moment is obtained as the magnetic field information sequence.

[0015] In one embodiment of the present invention, the local space coordinate system is constructed by:

[0016] A local coordinate origin is set; based on the local coordinate origin, the local space coordinate system is constructed; the local coordinate origin includes: a magnetic field source, an X-ray source or a camera for taking the positioning image; the relative positions among the magnetic field source, the X-ray source and the camera remain unchanged.

[0017] In one embodiment of the present invention, the converting of each of the image coordinates into a local space coordinate, when converting a single image coordinate into a local space coordinate, includes:

[0018] Based on the intrinsic parameter matrix of the camera, the image coordinates are converted into camera coordinates in a three-dimensional camera coordinate system; based on the local extrinsic parameter matrix of the camera, the camera coordinates are converted into local space coordinates;

[0019] The local extrinsic parameter matrix is ​​a pre-constructed matrix containing rotation and translation information of the camera in the local coordinate system.

[0020] In one embodiment of the present invention, the method for acquiring the magnetic field distribution includes:

[0021] The local spatial position and the magnetic field information at the same moving moment are taken as a group, and the local spatial position and the magnetic field information at each moving moment are matched respectively to obtain the magnetic field information at each local spatial position as the magnetic field distribution in the target environment.

[0022] In one embodiment of the present invention, determining the current position of the flat panel detector based on the magnetic field distribution and the current magnetic field information includes:

[0023] Based on the current magnetic field information, the local spatial position corresponding to the current magnetic field information is acquired in the magnetic field distribution as the current position of the flat panel detector.

[0024] Correspondingly, the present invention provides a flat panel detector positioning system, the system comprising:

[0025] An acquisition module is used to acquire a positioning image sequence and a magnetic field information sequence of the flat panel detector in a target environment based on time-sequential acquisition; the positioning image sequence includes: each positioning image containing the flat panel detector acquired in real time during the movement of the flat panel detector; the magnetic field information sequence includes: magnetic field information of the flat panel detector at each moving position acquired in real time during the movement of the flat panel detector;

[0026] A position extraction module, used for extracting the image coordinates of the flat panel detector in each positioning image; converting each image coordinate into a local space coordinate to obtain the local space position of the flat panel detector at each moving moment; the local space coordinate is the coordinate of the flat panel detector in a pre-constructed local space coordinate system; in the local space coordinate system, the relative positions between the devices used to locate the flat panel detector remain unchanged;

[0027] A magnetic field calibration module, used to perform one-to-one matching between each of the local spatial positions and each of the magnetic field information, and obtain the magnetic field information of the flat panel detector at each of the local spatial positions as the magnetic field distribution in the target environment;

[0028] A detector positioning module is used to obtain the current magnetic field information of the flat-panel detector; based on the magnetic field distribution and the current magnetic field information, determine the current position of the flat-panel detector

[0029] Correspondingly, the present invention provides a flat panel detector positioning device for positioning a flat panel detector, the device comprising:

[0030] A magnetic field source, used for generating a low-frequency magnetic field;

[0031] A camera, used for capturing a positioning image including the flat panel detector;

[0032] A magnetic field sensor, used to sense the magnetic field at the location of the flat panel detector to obtain magnetic field information;

[0033] a processing module, connected to the camera and the magnetic field sensor respectively, and used to position the flat panel detector using the flat panel detector positioning method as described above;

[0034] The relative positions of the magnetic field source, the camera and the X-ray source remain unchanged.

[0035] In one embodiment of the present invention, the device further comprises: a positioning identification member; the positioning identification member is arranged on a side of the flat-panel detector facing the camera and does not block a radiation receiving surface of the flat-panel detector.

[0036] Correspondingly, the present invention provides a computer-readable storage medium, wherein the computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the flat panel detector positioning method as described above is implemented.

[0037] As described above, the present application provides a flat panel detector positioning method, system, device and medium, which at least have the following features:

[0038] Beneficial effects:

[0039] By acquiring a positioning image sequence and a magnetic field information sequence of a flat-panel detector in a target environment; based on the positioning image, using visual positioning technology to acquire the local spatial position of the flat-panel detector in a pre-constructed local coordinate system at each moving moment; matching the local spatial position and magnetic field information at each moving moment to obtain the magnetic field distribution in the target environment, thereby realizing rapid calibration of the magnetic field distribution in the target environment; and by acquiring the current magnetic field information of the flat-panel detector in the target environment, based on the magnetic field distribution and the current magnetic field information, rapidly determining the current position of the flat-panel detector in the local coordinate system, not only can the magnetic field distribution in the changed environment be accurately acquired, thereby improving the positioning accuracy of the flat-panel detector relative to the X-ray source position, but also after the magnetic field distribution changes, there is no need to manually recalibrate the magnetic field distribution in space, thereby improving the positioning efficiency of the flat-panel detector relative to the X-ray source position. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Figure 1 A schematic diagram of a flow chart of a flat panel detector positioning method provided by the present application in one embodiment is shown.

[0041] Figure 2 A schematic diagram of modules of a flat panel detector positioning system provided by the present application in one embodiment is shown.

[0042] Figure 3 A schematic structural diagram of a flat panel detector positioning device provided by the present application in one embodiment is shown.

[0043] Description of Reference Numerals

[0044] S1~S4, steps; 200, flat panel detector positioning system; 201, acquisition module; 202, position extraction module; 203, magnetic field calibration module; 204, detector positioning module; A, flat panel detector; B, X-ray source; 1, magnetic field source; 2, camera; 3, magnetic field sensor; 4, processing module. DETAILED DESCRIPTION

[0045] The following describes the embodiments of the present application through specific examples, and those skilled in the art can easily understand other advantages and effects of the present application from the contents disclosed in this specification. The present application can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present application. It should be noted that the following embodiments and features in the embodiments can be combined with each other without conflict.

[0046] It should be noted that the illustrations provided in the following embodiments are only schematic illustrations of the basic concept of the present application, and thus the drawings only show components related to the present application rather than being drawn according to the number, shape and size of components in actual implementation. In actual implementation, the type, quantity and proportion of each component may be changed at will, and the component layout may also be more complicated.

[0047] To facilitate the understanding of the technical solutions provided by the present application, the relevant terms in the present application are explained before the specific embodiments, as follows:

[0048] Intrinsic parameter matrix: A matrix containing internal parameters such as the focal length of the camera, the coordinates of the principal point (optical center), and the physical size of the pixel, which is used to map points in the three-dimensional camera coordinate system to points in the two-dimensional image coordinate system.

[0049] Extrinsic parameter matrix: It is the transformation matrix from the world coordinate system to the camera coordinate system. It usually contains two rotation matrices and a translation vector. The rotation matrix describes the rotation of the camera coordinate axis relative to the world coordinate axis, and the translation vector describes the position of the camera in the world coordinate system.

[0050] The embodiments of the present application are described in detail below in conjunction with the accompanying drawings. In the absence of conflict, the features of the following embodiments and implementations can be combined with each other.

[0051] The following embodiments of the present application provide a method for positioning a flat-panel detector, which obtains a positioning image sequence and a magnetic field information sequence of the flat-panel detector in a target environment; based on the positioning image, uses visual positioning technology to obtain the local spatial position of the flat-panel detector in a pre-constructed local coordinate system at each moving moment; matches the local spatial position and magnetic field information at each moving moment to obtain the magnetic field distribution in the target environment, thereby realizing rapid calibration of the magnetic field distribution in the target environment; and, by obtaining the current magnetic field information of the flat-panel detector in the target environment, based on the magnetic field distribution and the current magnetic field information, quickly determines the current position of the flat-panel detector in the local coordinate system, which not only accurately obtains the magnetic field distribution in the changed environment, but also improves the positioning accuracy of the flat-panel detector relative to the X-ray source position, and after the magnetic field distribution changes, there is no need to manually recalibrate the magnetic field distribution in space, thereby improving the positioning efficiency of the flat-panel detector relative to the X-ray source position.

[0052] See also Figure 1 , showing a structural schematic diagram of a flat panel detector positioning method provided by the present invention in one embodiment.

[0053] like Figure 1As shown, in this embodiment, the flat panel detector positioning method provided by the present invention comprises the following steps:

[0054] Step S1, obtaining a positioning image sequence and a magnetic field information sequence based on time-series acquisition of a flat panel detector in a target environment;

[0055] The positioning image sequence includes: each positioning image containing the flat panel detector acquired in real time during the movement of the flat panel detector; the magnetic field information sequence includes: magnetic field information at each moving position of the flat panel detector acquired in real time during the movement of the flat panel detector;

[0056] Specifically, the flat-panel detector is moved in the target environment; during the movement of the flat-panel detector, the flat-panel detector is photographed in real time, and the magnetic field at the position where the flat-panel detector is located is sensed in real time to obtain the positioning image of the flat-panel detector at each movement moment as the positioning image sequence; and the magnetic field information of the flat-panel detector at each movement position is obtained as the magnetic field information sequence.

[0057] Optionally, the magnetic field information includes: magnetic field strength and magnetic field direction, etc.

[0058] Step S2, extracting the image coordinates of the flat panel detector in each of the positioning images; converting each of the image coordinates into a local space coordinate to obtain the local space position of the flat panel detector at each moving moment;

[0059] The local space coordinates are coordinates of the flat panel detector in a pre-constructed local space coordinate system; in the local space coordinate system, the relative positions between the devices used to position the flat panel detector remain unchanged.

[0060] Specifically, each of the positioning images is input into a pre-constructed extraction model to obtain each extraction result output by the extraction model; based on the extraction result, the image coordinates of the flat-panel detector in each of the positioning images are obtained; coordinate transformation is performed on each of the image coordinates to obtain the local spatial coordinates corresponding to each of the image coordinates; based on the movement time corresponding to each of the positioning images, the local spatial position of the flat-panel detector at each of the movement times is obtained.

[0061] Optionally, the extraction model is a pre-built neural network model for extracting a target extract; the target extract includes the flat panel detector.

[0062] Optionally, the local space coordinate system is constructed by:

[0063] A local coordinate origin is set; based on the local coordinate origin, the local space coordinate system is constructed; the local coordinate origin includes: a magnetic field source, an X-ray source or a camera for taking the positioning image; the relative positions among the magnetic field source, the X-ray source and the camera remain unchanged.

[0064] Optionally, the converting of each of the image coordinates into a local space coordinate, when converting a single image coordinate into a local space coordinate, includes:

[0065] Based on the intrinsic parameter matrix of the camera, the image coordinates are converted into camera coordinates in a three-dimensional camera coordinate system; based on the local extrinsic parameter matrix of the camera, the camera coordinates are converted into local space coordinates;

[0066] The local extrinsic parameter matrix includes information such as rotation and translation of the camera in the local coordinate system.

[0067] Optionally, the method for obtaining the local extrinsic parameter matrix includes:

[0068] The local space coordinate system is calibrated to determine the geometric relationship between the camera and the local space coordinate system; based on the geometric relationship, a local extrinsic parameter matrix of the camera relative to the local space coordinate system is constructed.

[0069] Optionally, the image coordinates of the upper left corner, the lower left corner, the upper right corner, the lower right corner or the center point of the extraction result are used as the image coordinates of the flat panel detector in the positioning image.

[0070] Exemplarily, the extraction result output by the extraction model is an identification box, and the coordinates of the upper left corner, lower left corner, upper right corner, lower right corner or center point of the identification box in the positioning image are used as the image coordinates of the flat panel detector in the positioning image.

[0071] It should be noted that the method for obtaining the local extrinsic parameter matrix is ​​the same as the method for obtaining the extrinsic parameter matrix of the camera relative to the world coordinate system. The local extrinsic parameter matrix can be obtained based on other existing methods for obtaining extrinsic parameter matrices, and this application does not impose any restrictions on this.

[0072] Step S3, matching each of the local spatial positions with each of the magnetic field information one by one, and obtaining the magnetic field information of the flat panel detector at each of the local spatial positions as the magnetic field distribution in the target environment;

[0073] Specifically, based on the correspondence between the local spatial position and the magnetic field information and the moving moment, the local spatial position and the magnetic field information at the same moving moment are taken as a group, and the local spatial position and the magnetic field information at each moving moment are matched respectively to obtain the magnetic field information at each local spatial position as the magnetic field distribution in the target environment.

[0074] Step S4, obtaining current magnetic field information of the flat panel detector, and determining the current position of the flat panel detector based on the magnetic field distribution and the current magnetic field information;

[0075] The current magnetic field information is the magnetic field information of the flat panel detector in the target environment.

[0076] Specifically, the magnetic field information of the flat-panel detector at its current position in the target environment is obtained, and based on the current magnetic field information, the local spatial position corresponding to the current magnetic field information is obtained in the magnetic field distribution as the current position of the flat-panel detector.

[0077] A flat-panel detector positioning method provided in the above embodiment obtains a positioning image sequence and a magnetic field information sequence of the flat-panel detector in a target environment; based on the positioning image, uses visual positioning technology to obtain the local spatial position of the flat-panel detector in a pre-constructed local coordinate system at each moving moment; matches the local spatial position and magnetic field information at each moving moment to obtain the magnetic field distribution in the target environment, thereby realizing rapid calibration of the magnetic field distribution in the target environment; and, by obtaining the current magnetic field information of the flat-panel detector in the target environment, based on the magnetic field distribution and the current magnetic field information, quickly determines the current position of the flat-panel detector in the local coordinate system, which not only accurately obtains the magnetic field distribution in the changed environment, but also improves the positioning accuracy of the flat-panel detector relative to the X-ray source position, and after the magnetic field distribution changes, there is no need to manually recalibrate the magnetic field distribution in space, thereby improving the positioning efficiency of the flat-panel detector relative to the X-ray source position.

[0078] like Figure 2 As shown, in this embodiment, the present invention provides a flat panel detector positioning system, including:

[0079] The acquisition module 201 is used to acquire a positioning image sequence and a magnetic field information sequence based on time-sequential acquisition of the flat panel detector in the target environment; the positioning image sequence includes: each positioning image containing the flat panel detector acquired in real time during the movement of the flat panel detector; the magnetic field information sequence includes: the magnetic field information of the flat panel detector at each moving position acquired in real time during the movement of the flat panel detector;

[0080] The position extraction module 202 is used to extract the image coordinates of the flat panel detector in each positioning image; convert each image coordinate into a local space coordinate to obtain the local space position of the flat panel detector at each moving moment; the local space coordinate is the coordinate of the flat panel detector in a pre-constructed local space coordinate system; in the local space coordinate system, the relative positions between the devices used to locate the flat panel detector remain unchanged;

[0081] A magnetic field calibration module 203 is used to perform one-to-one matching between each local spatial position and each magnetic field information, and obtain the magnetic field information of the flat panel detector at each local spatial position as the magnetic field distribution in the target environment;

[0082] The detector positioning module 204 is used to obtain the current magnetic field information of the flat-panel detector; and determine the current position of the flat-panel detector based on the magnetic field distribution and the current magnetic field information.

[0083] See also Figure 3 , showing a structural schematic diagram of a flat panel detector positioning device provided by the present invention in one embodiment.

[0084] like Figure 3 As shown, in this embodiment, the flat panel detector positioning device provided by the present invention is used to position the flat panel detector A, and the flat panel detector positioning device includes:

[0085] A magnetic field source 1, used for generating a low-frequency magnetic field;

[0086] Camera 2, used for capturing a positioning image including the flat panel detector A;

[0087] A magnetic field sensor 3 is used to sense the magnetic field at the location of the flat panel detector A to obtain magnetic field information;

[0088] The processing module 4 is connected to the camera 2 and the magnetic field sensor 3 respectively, and is used to obtain a positioning image sequence and a magnetic field information sequence of the flat panel detector in the target environment based on time series acquisition; extract the image coordinates of the flat panel detector in each positioning image; convert each image coordinate into a local space coordinate to obtain the local space position of the flat panel detector at each moving moment; respectively, one-to-one match each local space position with each magnetic field information to obtain the magnetic field information of the flat panel detector at each local space position as the magnetic field distribution in the target environment; and to obtain the current magnetic field information of the flat panel detector; based on the magnetic field distribution and the current magnetic field information, determine the current position of the flat panel detector;

[0089] The relative positions of the magnetic field source 1, the camera 2 and the X-ray source B remain unchanged.

[0090] Optionally, the magnetic field source 1 includes: a low-frequency magnetic field generating device such as an electromagnet.

[0091] Optionally, the magnetic field sensor 3 is an internal magnetic field sensing element in the flat-panel detector A, or an external magnetic field sensing device arranged on the flat-panel detector A; when the magnetic field sensor 3 is the external magnetic field sensing device, the magnetic field sensor 3 is arranged at a position outside the radiation receiving surface of the flat-panel detector A.

[0092] Optionally, the device also includes: a positioning identification member; the positioning identification member is arranged on the side of the flat-panel detector A facing the camera, and does not block the radiation receiving surface of the flat-panel detector A, so that the camera 2 can photograph the positioning identification member without blocking the radiation receiving surface.

[0093] Optionally, the positioning identification component includes: a sticker with a QR code printed on the surface.

[0094] The present application embodiment also provides a computer-readable storage medium. A person of ordinary skill in the art can understand that all or part of the steps in the method for implementing the above embodiment can be completed by a program to instruct the processor, and the program can be stored in a computer-readable storage medium, and the storage medium is a non-transitory medium, such as a random access memory, a read-only memory, a flash memory, a hard disk, a solid-state hard disk, a magnetic tape, a floppy disk, an optical disc, and any combination thereof. The above storage medium can be any available medium that can be accessed by a computer or a data storage device such as a server or a data center that includes one or more available media integrated. The available medium can be a magnetic medium (e.g., a floppy disk, a hard disk, a tape), an optical medium (e.g., a digital video disc (DVD)), or a semiconductor medium (e.g., a solid-state hard disk (SSD)), etc.

[0095] The present application embodiment may also provide a computer program product, the computer program product including one or more computer instructions. When the computer instructions are loaded and executed on a computing device, the process or function described in the embodiment of the present application is generated in whole or in part. The computer instructions may be stored in a computer-readable storage medium, or transmitted from one computer-readable storage medium to another computer-readable storage medium, for example, the computer instructions may be transmitted from a website site, computer or data center by wired (e.g., coaxial cable, optical fiber, digital subscriber line (DSL)) or wireless (e.g., infrared, wireless, microwave, etc.) mode to another website site, computer or data center.

[0096] When the computer program product is executed by a computer, the computer executes the method described in the above method embodiment. The computer program product may be a software installation package, and when the above method is required, the computer program product may be downloaded and executed on a computer.

[0097] The descriptions of the processes or structures corresponding to the above-mentioned figures have different emphases. For parts that are not described in detail in a certain process or structure, please refer to the relevant descriptions of other processes or structures.

[0098] The above embodiments are merely illustrative of the principles and effects of the present application and are not intended to limit the present application. Anyone familiar with the technology may modify or change the above embodiments without violating the spirit and scope of the present application. Therefore, all equivalent modifications or changes made by a person of ordinary skill in the art without departing from the spirit and technical ideas disclosed in the present application shall still be covered by the claims of the present application.

Claims

1. A flat panel detector positioning method, characterized in that: The method comprises: Acquire a positioning image sequence and a magnetic field information sequence based on time-sequential acquisition of the flat panel detector in the target environment; the positioning image sequence includes: each positioning image containing the flat panel detector acquired in real time during the movement of the flat panel detector; the magnetic field information sequence includes: magnetic field information of the flat panel detector at each moving position acquired in real time during the movement of the flat panel detector; Extracting the image coordinates of the flat panel detector in each of the positioning images; converting each of the image coordinates into a local space coordinate to obtain the local space position of the flat panel detector at each moving moment; Matching each of the local spatial positions with each of the magnetic field information in a one-to-one correspondence, respectively, to obtain the magnetic field information of the flat panel detector at each of the local spatial positions as the magnetic field distribution in the target environment; Acquire current magnetic field information of the flat panel detector; determine the current position of the flat panel detector based on the magnetic field distribution and the current magnetic field information; The local space coordinates are coordinates of the flat panel detector in a pre-constructed local space coordinate system; in the local space coordinate system, the relative positions between the devices used to position the flat panel detector remain unchanged.

2. The method according to claim 1, characterized in that: The method for acquiring the positioning image sequence and the magnetic field information sequence includes: During the movement of the flat panel detector, photographing the flat panel detector in real time, and sensing the magnetic field of the flat panel detector at each moving position in real time; A positioning image of the flat panel detector at each moving moment is obtained as the positioning image sequence; and magnetic field information of the flat panel detector at each moving moment is obtained as the magnetic field information sequence.

3. The method according to claim 1, characterized in that: The local space coordinate system is constructed in the following manner: A local coordinate origin is set; based on the local coordinate origin, the local space coordinate system is constructed; the local coordinate origin includes: a magnetic field source, an X-ray source or a camera for taking the positioning image; the relative positions among the magnetic field source, the X-ray source and the camera remain unchanged.

4. The method according to claim 1, characterized in that: The converting each of the image coordinates into a local space coordinate, when converting a single image coordinate into a local space coordinate, includes: Based on the intrinsic parameter matrix of the camera, the image coordinates are converted into camera coordinates in a three-dimensional camera coordinate system; Based on the local extrinsic matrix of the camera, converting the camera coordinates into local space coordinates; The local extrinsic parameter matrix is ​​a pre-constructed matrix containing rotation and translation information of the camera in the local coordinate system.

5. The method according to claim 1, characterized in that The method for obtaining the magnetic field distribution includes: The local spatial position and the magnetic field information at the same moving moment are taken as a group, and the local spatial position and the magnetic field information at each moving moment are matched respectively to obtain the magnetic field information at each local spatial position as the magnetic field distribution in the target environment.

6. The method according to claim 1, characterized in that The determining the current position of the flat panel detector based on the magnetic field distribution and the current magnetic field information includes: Based on the current magnetic field information, the local spatial position corresponding to the current magnetic field information is acquired in the magnetic field distribution as the current position of the flat panel detector.

7. A flat panel detector positioning system, characterized in that: include: An acquisition module is used to acquire a positioning image sequence and a magnetic field information sequence of the flat panel detector in a target environment based on time-series acquisition; The positioning image sequence includes: each positioning image containing the flat panel detector acquired in real time during the movement of the flat panel detector; the magnetic field information sequence includes: magnetic field information of the flat panel detector at each moving position acquired in real time during the movement of the flat panel detector; A position extraction module, used to extract the image coordinates of the flat panel detector in each positioning image; convert each image coordinate into a local space coordinate to obtain the local space position of the flat panel detector at each moving moment; the local space coordinate is the coordinate of the flat panel detector in a pre-constructed local space coordinate system; in the local space coordinate system, the relative positions between the devices used to locate the flat panel detector remain unchanged; A magnetic field calibration module, used to perform one-to-one matching between each of the local spatial positions and each of the magnetic field information, and obtain the magnetic field information of the flat panel detector at each of the local spatial positions as the magnetic field distribution in the target environment; The detector positioning module is used to obtain the current magnetic field information of the flat-panel detector; based on the magnetic field distribution and the current magnetic field information, determine the current position of the flat-panel detector.

8. A flat panel detector positioning device, characterized in that: Used to position a flat panel detector, the device comprises: A magnetic field source, used for generating a low-frequency magnetic field; A camera, used for capturing a positioning image including the flat panel detector; A magnetic field sensor, used to sense the magnetic field at the location of the flat panel detector to obtain magnetic field information; a processing module, connected to the camera and the magnetic field sensor, respectively, and configured to position the flat panel detector using the flat panel detector positioning method according to any one of claims 1 to 6; The relative positions of the magnetic field source, the camera and the X-ray source remain unchanged.

9. The device according to claim 8, characterized in that The device further comprises: a positioning identification member; the positioning identification member is arranged on a side of the flat panel detector facing the camera and does not block a radiation receiving surface of the flat panel detector.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the program is executed, the flat panel detector positioning method according to any one of claims 1 to 6 is implemented.

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