Tracking method and device based on magnetic navigation, computer equipment, readable storage medium and program product

Abstract

The invention relates to a tracking method and device based on magnetic navigation, computer equipment, a computer readable storage medium and a computer program product, relates to the technical field of medicine, and can improve the intraoperative tracking accuracy. The method comprises the following steps: constructing a second three-dimensional model corresponding to a first three-dimensional model in a visual coordinate system, and determining a first mapping relation between a CT coordinate system and the visual coordinate system according to the first three-dimensional model and the second three-dimensional model; acquiring a plurality of target object sampling points according to a moving track of a surgical tool provided with a magnetic sensor on the surface of the target object, and determining a second mapping relation between the magnetic navigation coordinate system and the visual coordinate system according to the target object sampling points and a second three-dimensional model; according to the first mapping relation, the second three-dimensional model of the target object is displayed in a visual interface, and according to the second mapping relation, the position, relative to the second three-dimensional model, of a surgical tool provided with a magnetic sensor is displayed in the visual interface.

Description

Technical Field

[0001] The present application relates to the field of medical technology, and in particular to a tracking method, apparatus, computer device, computer-readable storage medium and computer program product based on magnetic navigation. Background Art

[0002] With the development of medical technology, relevant information of the surgical process can be tracked through tracking technology to understand the current operation status in a timely manner.

[0003] In the related technologies, intraoperative tracking technology mainly adopts optical navigation technology, which mainly uses depth cameras and reflective balls to capture and identify the posture of the target. However, due to the large area of ​​the reflective ball bracket, it is easy to be blocked during the operation, resulting in the need for re-alignment or reduced tracking accuracy, which has a significant negative impact on the accuracy of intraoperative tracking. Summary of the invention

[0004] Based on this, it is necessary to provide a tracking method, device, computer equipment, computer-readable storage medium and computer program product based on magnetic navigation to address the above technical problems.

[0005] In a first aspect, the present application provides a tracking method based on magnetic navigation, comprising:

[0006] Acquire a first three-dimensional model of the target object in the CT coordinate system;

[0007] Constructing a second three-dimensional model corresponding to the first three-dimensional model in a visual coordinate system, and determining a first mapping relationship between the CT coordinate system and the visual coordinate system according to the first three-dimensional model and the second three-dimensional model;

[0008] Acquire a plurality of target sampling points of the target in a magnetic navigation coordinate system according to a movement trajectory of a surgical tool equipped with a magnetic sensor on the surface of the target, and determine a second mapping relationship between the magnetic navigation coordinate system and the visual coordinate system according to the target sampling points and the second three-dimensional model;

[0009] The second three-dimensional model of the target object is displayed in a visualization interface according to the first mapping relationship, and the position of the surgical tool provided with the magnetic sensor relative to the second three-dimensional model is displayed in the visualization interface according to the second mapping relationship.

[0010] In one embodiment, determining a second mapping relationship between the magnetic navigation coordinate system and the visual coordinate system according to the target object sampling point and the second three-dimensional model includes:

[0011] Acquire a second point cloud corresponding to the second three-dimensional model;

[0012] Registering the target object sampling point and the second point cloud, and determining magnetic navigation coordinate system rotation information and magnetic navigation coordinate system translation information for transforming from the magnetic navigation coordinate system to the visual coordinate system according to the registration result;

[0013] A second mapping relationship between the magnetic navigation coordinate system and the visual coordinate system is obtained according to the rotation information of the magnetic navigation coordinate system and the translation information of the magnetic navigation coordinate system.

[0014] In one embodiment, registering the target object sampling points and the second point cloud includes:

[0015] Pre-registering the target object sampling points and the second point cloud;

[0016] Determine, according to the candidate mapping relationship between the magnetic navigation coordinate system and the visual coordinate system obtained by the pre-registration, a first corresponding point of the target object sampling point in the visual coordinate system, and a second corresponding point of the first corresponding point in the magnetic navigation coordinate system;

[0017] Determining accuracy information of the pre-registration correspondence according to an error between the second corresponding point and the target object sampling point;

[0018] A registration result is determined according to the candidate mapping relationship obtained by the pre-registration whose accuracy information satisfies the accuracy condition.

[0019] In one embodiment, determining the accuracy information of the pre-registration correspondence according to the error between the second corresponding point and the target object sampling point includes:

[0020] For the target object sampling point, obtaining an error distance between the second corresponding point and the target object sampling point;

[0021] According to each of the error distances, accuracy information corresponding to the pre-registration is determined.

[0022] In one embodiment, determining a first mapping relationship between the CT coordinate system and the visual coordinate system according to the first three-dimensional model and the second three-dimensional model includes:

[0023] Acquire a first point cloud corresponding to the first three-dimensional model and a second point cloud corresponding to the second three-dimensional model;

[0024] Registering the first point cloud and the second point cloud, and determining CT coordinate system rotation information and CT coordinate system translation information for transforming from the CT coordinate system to the visual coordinate system according to the registration result;

[0025] A first mapping relationship between the CT coordinate system and the visual coordinate system is obtained according to the CT coordinate system rotation information and the CT coordinate system translation information.

[0026] In one embodiment, the step of obtaining a first three-dimensional model of the target object in a CT coordinate system includes:

[0027] Acquire multiple preoperative CT images corresponding to the target object;

[0028] For a same visible point in the plurality of preoperative CT images, determining a reconstructed position of the visible point in the CT coordinate system according to the visible point position and CT projection parameters of the visible point in each of the preoperative CT images;

[0029] A first three-dimensional model of the target object in the CT coordinate system is constructed according to the reconstructed position of each of the visible points.

[0030] In a second aspect, the present application also provides a tracking device based on magnetic navigation, comprising:

[0031] A first model acquisition module, used to acquire a first three-dimensional model of the target object in a CT coordinate system;

[0032] a first mapping relationship acquisition module, configured to construct a second three-dimensional model corresponding to the first three-dimensional model in a visual coordinate system, and determine a first mapping relationship between the CT coordinate system and the visual coordinate system according to the first three-dimensional model and the second three-dimensional model;

[0033] a second mapping relationship acquisition module, configured to acquire a plurality of target object sampling points of the target object in a magnetic navigation coordinate system according to a movement trajectory of a surgical tool equipped with a magnetic sensor on the surface of the target object, and determine a second mapping relationship between the magnetic navigation coordinate system and the visual coordinate system according to the target object sampling points and the second three-dimensional model;

[0034] A tracking module is used to display the second three-dimensional model of the target object in a visualization interface according to the first mapping relationship, and to display the position of the surgical tool provided with the magnetic sensor relative to the second three-dimensional model in the visualization interface according to the second mapping relationship.

[0035] In a third aspect, the present application further provides a computer device, including a memory and a processor, wherein the memory stores a computer program, and when the processor executes the computer program, the following steps are implemented:

[0036] Acquire a first three-dimensional model of the target object in the CT coordinate system;

[0037] Constructing a second three-dimensional model corresponding to the first three-dimensional model in a visual coordinate system, and determining a first mapping relationship between the CT coordinate system and the visual coordinate system according to the first three-dimensional model and the second three-dimensional model;

[0038] Acquire a plurality of target object sampling points of the target object in a magnetic navigation coordinate system according to a movement trajectory of a surgical tool equipped with a magnetic sensor on the surface of the target object, and determine a second mapping relationship between the magnetic navigation coordinate system and the visual coordinate system according to the target object sampling points and the second three-dimensional model;

[0039] According to the first mapping relationship, the second three-dimensional model of the target object is displayed in a visualization interface, and according to the second mapping relationship, the position of the surgical tool provided with the magnetic sensor relative to the second three-dimensional model is displayed in the visualization interface.

[0040] In a fourth aspect, the present application further provides a computer-readable storage medium having a computer program stored thereon, wherein when the computer program is executed by a processor, the following steps are implemented:

[0041] Acquire a first three-dimensional model of the target object in the CT coordinate system;

[0042] Constructing a second three-dimensional model corresponding to the first three-dimensional model in a visual coordinate system, and determining a first mapping relationship between the CT coordinate system and the visual coordinate system according to the first three-dimensional model and the second three-dimensional model;

[0043] Acquire a plurality of target object sampling points of the target object in a magnetic navigation coordinate system according to a movement trajectory of a surgical tool equipped with a magnetic sensor on the surface of the target object, and determine a second mapping relationship between the magnetic navigation coordinate system and the visual coordinate system according to the target object sampling points and the second three-dimensional model;

[0044] According to the first mapping relationship, the second three-dimensional model of the target object is displayed in a visualization interface, and according to the second mapping relationship, the position of the surgical tool provided with the magnetic sensor relative to the second three-dimensional model is displayed in the visualization interface.

[0045] In a fifth aspect, the present application further provides a computer program product, including a computer program, which implements the following steps when executed by a processor:

[0046] Acquire a first three-dimensional model of the target object in the CT coordinate system;

[0047] Constructing a second three-dimensional model corresponding to the first three-dimensional model in a visual coordinate system, and determining a first mapping relationship between the CT coordinate system and the visual coordinate system according to the first three-dimensional model and the second three-dimensional model;

[0048] Acquire a plurality of target sampling points of the target in a magnetic navigation coordinate system according to a movement trajectory of a surgical tool equipped with a magnetic sensor on the surface of the target, and determine a second mapping relationship between the magnetic navigation coordinate system and the visual coordinate system according to the target sampling points and the second three-dimensional model;

[0049] The second three-dimensional model of the target object is displayed in a visualization interface according to the first mapping relationship, and the position of the surgical tool provided with the magnetic sensor relative to the second three-dimensional model is displayed in the visualization interface according to the second mapping relationship.

[0050] The above-mentioned tracking method, device, computer equipment, computer-readable storage medium and computer program product based on magnetic navigation can, on the one hand, obtain a first three-dimensional model of the target object in the CT coordinate system, and then construct a second three-dimensional model corresponding to the first three-dimensional model in the visual coordinate system, and determine the first mapping relationship between the CT coordinate system and the visual coordinate system based on the first three-dimensional model and the second three-dimensional model; on the other hand, according to the movement trajectory of the surgical tool equipped with a magnetic sensor on the surface of the target object, obtain multiple target sampling points of the target object in the magnetic navigation coordinate system, and determine the second mapping relationship between the magnetic navigation coordinate system and the visual coordinate system based on the target sampling points and the second three-dimensional model; and then, according to the first mapping relationship, the second three-dimensional model of the target object can be displayed in the visualization interface, and, according to the second mapping relationship, the position of the surgical tool equipped with a magnetic sensor relative to the second three-dimensional model can be displayed in the visualization interface. In this embodiment, by determining a first mapping relationship between the CT coordinate system and the visual coordinate system based on the first three-dimensional model and the second three-dimensional model, and determining a second mapping relationship between the magnetic navigation coordinate system and the visual coordinate system based on the target object sampling point and the second three-dimensional model, the mapping of the CT coordinate system and the magnetic navigation coordinate system to the visual coordinate system can be achieved, and then the intraoperative state of the target object and the intraoperative state of the surgical tools can be aligned and tracked in real time in the three-dimensional digital virtual scene according to the first mapping relationship and the second mapping relationship, thereby reducing the tracking error, and displaying it in a visual interface so that the user can perceive the tracking results in time, effectively improving the tracking accuracy and safety. BRIEF DESCRIPTION OF THE DRAWINGS

[0051] In order to more clearly illustrate the technical solutions in the embodiments of the present application or related technologies, the drawings required for use in the embodiments of the present application or related technical descriptions will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

[0052] Figure 1 is a schematic flow chart of a tracking method based on magnetic navigation in one embodiment;

[0053] Figure 2 is a schematic diagram of coordinate points of a magnetic sensor in a magnetic navigation coordinate system in one embodiment;

[0054] Figure 3 is a flow chart of another tracking method based on magnetic navigation in one embodiment;

[0055] Figure 4 A schematic diagram of the contents of a visualization interface in one embodiment;

[0056] Figure 5 A schematic diagram of a flow chart of a step of obtaining a registration result in one embodiment;

[0057] Figure 6 is a structural block diagram of a tracking device based on magnetic navigation in one embodiment;

[0058] Figure 7 The figure is a diagram of the internal structure of a computer device in one embodiment. DETAILED DESCRIPTION

[0059] In order to make the purpose, technical solution and advantages of the present application more clearly understood, the present application is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0060] In one embodiment, Figure 1 As shown, a tracking method based on magnetic navigation is provided. This embodiment uses the method applied to a terminal as an example. For example, the terminal may be, but is not limited to, various medical devices, personal computers, laptop computers, tablet computers, etc. It can be understood that the method can also be applied to a server, and can also be applied to a system including a terminal and a server, and is implemented through the interaction between the terminal and the server. In this embodiment, the method includes the following steps:

[0061] S101, obtaining a first three-dimensional model of a target object in a CT coordinate system.

[0062] The CT coordinate system is a three-dimensional coordinate system used for three-dimensional reconstruction based on a computed tomography (CT) image. In one example, the CT coordinate system may be defined according to the isocenter of the CT system at zero rotation.

[0063] The target object may be a designated tissue structure, such as a tissue structure to be operated on or a tissue structure to be monitored during surgery. In some examples, the target object may include bone tissue or other soft tissues.

[0064] In this step, a three-dimensional model reconstructed for the target object with the CT coordinate system as the reference system can be obtained. To facilitate distinction from other three-dimensional models described below, the three-dimensional model of the target object in the CT coordinate system is referred to as the first three-dimensional model.

[0065] In some embodiments, a first three-dimensional model of the target object can be acquired in advance. For example, the first three-dimensional model can be pre-constructed based on CT images collected during a physical examination; or, the first three-dimensional model can be constructed based on preoperative CT images collected on an operating table.

[0066] S102: construct a second three-dimensional model corresponding to the first three-dimensional model in the visual coordinate system, and determine a first mapping relationship between the CT coordinate system and the visual coordinate system according to the first three-dimensional model and the second three-dimensional model.

[0067] The visual coordinate system may be a coordinate system in a fictitious three-dimensional visualization scene, and the visual coordinate system may be used to assist in constructing each virtual object in the virtual three-dimensional scene, for example, by using the visual coordinate system as a reference to set the position of each virtual object in the virtual three-dimensional visualization scene. In some embodiments, the visual coordinate system may be a coordinate system used in a visualization application, wherein the visualization application may provide an application of a three-dimensional visualization scene screen, and the visualization application may provide a visualization interface, through which a user may browse to the three-dimensional visualization scene screen.

[0068] Specifically, a visual coordinate system can be pre-constructed, and the setting of the visual coordinate system can be different from that of the CT coordinate system. For example, the CT coordinate system is determined based on the settings of the CT equipment manufacturer or related CT projection parameters, while the visual coordinate system can be set by the developer of the visualization application, thereby obtaining different visual coordinate systems and CT coordinate systems.

[0069] After constructing the visual coordinate system, a three-dimensional model corresponding to the first three-dimensional model can be constructed in the visual coordinate system. The three-dimensional model can be the same as the first three-dimensional model, such as having the same structure, but the three-dimensional model is a model with the visual coordinate system as the reference system. For ease of distinction, the three-dimensional model with the visual coordinate system as the reference system is called the second three-dimensional model.

[0070] It is understandable that since the first three-dimensional model and the second three-dimensional model are constructed based on different reference systems respectively, when the first three-dimensional model moves, the second three-dimensional model may not be able to directly adjust the posture according to the corresponding posture change of the first three-dimensional model in the CT coordinate system. For example, when the first three-dimensional model moves from position a to position b in the CT coordinate system, the second three-dimensional model does not move from position a to position b in the visual coordinate system, but moves from position c to position d.

[0071] In this regard, in the present embodiment, the mapping relationship between the CT coordinate system and the visual coordinate system can be first identified based on the first three-dimensional model and the second three-dimensional model. For ease of distinction, the mapping relationship from the CT coordinate system to the visual coordinate system is referred to as the first mapping relationship. Specifically, since the position of the first three-dimensional model in the CT coordinate system and the position of the second three-dimensional model in the visual coordinate system are known, and the first three-dimensional model and the second three-dimensional model are three-dimensional models constructed based on the same target object, that is, there is a corresponding relationship between the first three-dimensional model and the second three-dimensional model, therefore, the first mapping relationship between the CT coordinate system and the visual coordinate system can be determined based on the corresponding relationship between the first three-dimensional model in the CT coordinate system and the second three-dimensional model in the visual coordinate system, and subsequently the position changes of the target object during the operation can be tracked according to the first mapping relationship and displayed on the visualization interface.

[0072] S103, acquiring a plurality of target sampling points of the target in the magnetic navigation coordinate system according to the movement trajectory of the surgical tool equipped with the magnetic sensor on the surface of the target, and determining a second mapping relationship between the magnetic navigation coordinate system and the visual coordinate system according to the target sampling points and the second three-dimensional model.

[0073] In the related art, optical navigation technology uses a depth camera and a reflective ball to capture and identify the posture of the target object. However, since the reflective ball bracket used therein is easily blocked by the user, it will have a significant negative impact on the tracking accuracy.

[0074] In this regard, magnetic navigation can be used to track the specified tracking object (such as surgical tools). Magnetic navigation is a technology that uses magnetic field signals to achieve tracking. In the magnetic navigation system, a specific magnetic field can be generated by a signal source, and then the magnetic field signal is detected by a magnetic sensor, and the corresponding position is identified based on the strength and direction information of the magnetic field signal.

[0075] In this embodiment, the magnetic navigation system has a corresponding magnetic navigation coordinate system, which is also called the coordinate system of the electromagnetic tracking system. In some examples, the magnetic navigation coordinate system is defined by the position of a sensor with 6 degrees of freedom rigidly connected to the imaging table, and the sensor will be used as a stable reference to observe and record each electromagnetic measurement.

[0076] In a specific implementation, a magnetic sensor may be pre-set on the surgical tool, so that the position of the surgical tool in the magnetic navigation coordinate system may be determined by the magnetic sensor. For example, Figure 2 The coordinate positions of several magnetic sensors are shown. Then, the user can use the surgical tool equipped with the magnetic sensor to move on the surface of the target object, and the terminal can obtain multiple target sampling points of the target object in the magnetic navigation coordinate system according to the movement trajectory of the surgical tool on the surface of the target object.

[0077] For example, the magnetic sensor can be set at one end of the surgical tool that contacts the target (i.e., the contact end), and then multiple target sampling points corresponding to the actual target in the magnetic navigation coordinate system can be obtained based on the coordinate position of the magnetic sensor during the movement of the surgical tool. For another example, if the position where the magnetic sensor is set is a certain distance from the contact end of the surgical tool, the coordinate position of the contact end in the magnetic navigation coordinate system can be determined based on the relative position relationship between the magnetic sensor and the contact end, and then multiple target sampling points can be obtained based on the movement trajectory of the contact end on the surface of the target. In some examples, if the surgical tool is a surgical needle, nonlinear least squares optimization can be used to determine the position of the surgical needle in the magnetic navigation coordinate system, and then the surgical needle can be registered in the three-dimensional visualization scene based on the position.

[0078] Taking bone tissue as the target object as an example, since the multiple bone sampling points are obtained by sampling the actual bone tissue, and the second three-dimensional model is obtained based on the actual bone tissue structure, there are points on the second three-dimensional model corresponding to the bone sampling points, that is, there is also a corresponding relationship between the multiple bone sampling points and the second three-dimensional model. In this step, the second mapping relationship between the magnetic navigation coordinate system and the visual coordinate system can be determined based on the bone sampling points and the second three-dimensional model.

[0079] In some embodiments, Figure 3 As shown, the CT coordinate system and the magnetic navigation coordinate system can be calibrated first, and then the CT coordinate system and the magnetic navigation coordinate system can be mapped. By calibrating the coordinate system, the position representation of the same object in the CT coordinate system and the magnetic navigation coordinate system can be determined, the standard can be unified, the accuracy of subsequent measurements can be ensured, and the errors caused by inconsistent coordinate systems can be reduced. In an example, the conversion positioning from the magnetic navigation coordinate system to the CT coordinate system can be achieved according to the following method:

[0080]

[0081] in, is the magnetic navigation coordinate system matrix obtained based on the CT coordinate system transformation, is the coordinate system matrix after CT reconstruction, is the coordinate system matrix of the magnetic sensor, It is the original coordinate system of magnetic navigation.

[0082] S104, displaying a second three-dimensional model of the target object in the visualization interface according to the first mapping relationship, and displaying a position of a surgical tool provided with a magnetic sensor relative to the second three-dimensional model in the visualization interface according to the second mapping relationship.

[0083] In this step, after obtaining the first mapping relationship and the second mapping relationship, the target object and the surgical tool provided with the magnetic sensor can be tracked and displayed in the visualization interface. On the one hand, the second three-dimensional model in the visualization interface can be displayed corresponding to the target object in the real world. By displaying the second three-dimensional model in the visualization interface, the situation of the target object can be intuitively understood. For example, when the bone structure is slightly displaced due to cutting by the surgical tool, it can be displayed accordingly in the visualization interface; on the other hand, the position of the surgical tool relative to the second three-dimensional model can also be displayed accordingly. For example, Figure 4 As shown, the second three-dimensional model corresponding to the target object and the points collected by the surgical needle on the target object are displayed in the visualization interface.

[0084] The above-mentioned tracking method based on magnetic navigation can, on the one hand, obtain a first three-dimensional model of the target object in the CT coordinate system, and then construct a second three-dimensional model corresponding to the first three-dimensional model in the visual coordinate system, and determine a first mapping relationship between the CT coordinate system and the visual coordinate system based on the first three-dimensional model and the second three-dimensional model; on the other hand, according to the movement trajectory of the surgical tool equipped with a magnetic sensor on the surface of the target object, obtain multiple target sampling points of the target object in the magnetic navigation coordinate system, and determine the second mapping relationship between the magnetic navigation coordinate system and the visual coordinate system based on the target sampling points and the second three-dimensional model; and then, according to the first mapping relationship, the second three-dimensional model of the target object can be displayed in the visualization interface, and, according to the second mapping relationship, the position of the surgical tool equipped with a magnetic sensor relative to the second three-dimensional model can be displayed in the visualization interface. In this embodiment, by determining a first mapping relationship between the CT coordinate system and the visual coordinate system based on the first three-dimensional model and the second three-dimensional model, and determining a second mapping relationship between the magnetic navigation coordinate system and the visual coordinate system based on the target object sampling point and the second three-dimensional model, the mapping of the CT coordinate system and the magnetic navigation coordinate system to the visual coordinate system can be achieved, and then the intraoperative state of the target object and the intraoperative state of the surgical tools can be aligned and tracked in real time in the three-dimensional digital virtual scene according to the first mapping relationship and the second mapping relationship, thereby reducing the tracking error, and displaying it in a visual interface so that the user can perceive the tracking results in time, effectively improving the tracking accuracy and safety.

[0085] In addition, this application helps to improve the accuracy and safety of surgery by improving tracking accuracy and safety, thereby improving the quality and efficiency of surgery.

[0086] In one embodiment, in step S102, determining a first mapping relationship between the CT coordinate system and the visual coordinate system according to the first three-dimensional model and the second three-dimensional model may include the following steps:

[0087] Acquire a first point cloud corresponding to the first three-dimensional model and a second point cloud corresponding to the second three-dimensional model; align the first point cloud and the second point cloud, and determine the CT coordinate system rotation information and the CT coordinate system translation information for transforming from the CT coordinate system to the visual coordinate system based on the alignment result; obtain a first mapping relationship between the CT coordinate system and the visual coordinate system based on the CT coordinate system rotation information and the CT coordinate system translation information.

[0088] In a specific implementation, the first three-dimensional model and the second three-dimensional model can be respectively composed of multiple points in the coordinate system, that is, the three-dimensional model is composed of corresponding point clouds. For the sake of ease of distinction, the point cloud constituting the first three-dimensional model is called the first point cloud, and the point cloud constituting the second three-dimensional model is called the second point cloud.

[0089] After obtaining the first point cloud and the second point cloud, the first point cloud and the second point cloud can be registered, and then the CT coordinate system rotation information and the CT coordinate system translation information that are transformed from the CT coordinate system to the visual coordinate system can be obtained according to the registration result. The CT coordinate system rotation information and the CT coordinate system translation information can then be used as a first mapping relationship. Subsequently, for any point in the CT coordinate system, the point can be rotated and translated according to the CT coordinate system rotation information and the CT coordinate system translation information to obtain the corresponding point in the visual coordinate system.

[0090] In some embodiments, point cloud registration can be performed based on an ICP (Iterative Closest Point) registration algorithm. For example, the centroids of the first point cloud and the second point cloud are defined as follows:

[0091]

[0092]

[0093] Among them, qi is a point in the first point cloud Qi, and pi is a point in the second point cloud Pi.

[0094] Then proceed as follows:

[0095]

[0096]

[0097] In the above formula, represents the rotation angle of the camera relative to the Pi point cloud, and t represents the translation of the camera.

[0098] in:

[0099]

[0100] =

[0101] =

[0102] Then set The objective function is simplified to:

[0103]

[0104] Assume R * , t * is the optimal solution, then:

[0105]

[0106]

[0107] Where R * It can be deduced as:

[0108]

[0109] =

[0110] =

[0111] =

[0112] Let W = , through singular value decomposition (SVD):

[0113] W=

[0114] When W is full rank, then:

[0115]

[0116] And corresponding to the unique U, V combination, correspondingly:

[0117]

[0118]

[0119] in, is the CT coordinate system rotation information, It is the translation information of CT coordinate system.

[0120] In this embodiment, by aligning the first point cloud and the second point cloud, the CT coordinate system rotation information and the CT coordinate system translation information transformed from the CT coordinate system to the visual coordinate system can be accurately obtained, providing a reliable calculation basis for the subsequent mapping of points in the CT coordinate system to the visual coordinate system.

[0121] In one embodiment, in step S101, obtaining a first three-dimensional model of the target object in a CT coordinate system may include the following steps:

[0122] S1011, acquiring multiple preoperative CT images corresponding to the target object.

[0123] In some embodiments, a CT imaging device may be used to scan and photograph the target object before surgery to obtain a plurality of preoperative CT images corresponding to the target object.

[0124] S1012, for multiple visible points corresponding to the same spatial point in multiple preoperative CT images, determine a reconstructed position of the spatial point in the CT coordinate system according to the visible point position and CT projection parameters of the visible point in each preoperative CT image.

[0125] In a specific implementation, multiple preoperative CT images can capture the same object from different angles or different positions, that is, multiple preoperative CT images can contain image information for the same spatial point. In this regard, visible points corresponding to the same spatial point can be determined from multiple preoperative CT images to obtain multiple visible points, and then the position of the visible point in the CT coordinate system, that is, the reconstructed position, is calculated based on the visible point position of each visible point in the preoperative CT image and the CT projection parameters used when performing CT scanning. In some embodiments, the CT projection parameters include the gantry angle, the source-detector distance, the isocentric position, and the pixel scale. The spatial point can be reconstructed into a three-dimensional CT coordinate system based on the visible point position and the above-mentioned CT projection parameters. The above-mentioned processing is performed for each visible point corresponding to the same spatial point in multiple preoperative CT images, and the reconstructed position of each spatial point in the CT coordinate system can be obtained.

[0126] S1013: construct a first three-dimensional model of the target object in the CT coordinate system according to the reconstructed position of each spatial point.

[0127] Furthermore, the reconstructed positions of the various spatial points may be combined to construct a first three-dimensional model of the target object in the CT coordinate system.

[0128] In this embodiment, a plurality of preoperative CT images and CT projection parameters can be used to quickly and accurately reconstruct a first three-dimensional model of the target object in the CT coordinate system.

[0129] In one embodiment, in step S103, determining the second mapping relationship between the magnetic navigation coordinate system and the visual coordinate system according to the target object sampling points and the second three-dimensional model may include the following steps:

[0130] Acquire a second point cloud corresponding to the second three-dimensional model; align the target object sampling points and the second point cloud, and determine the magnetic navigation coordinate system rotation information and the magnetic navigation coordinate system translation information for transforming from the magnetic navigation coordinate system to the visual coordinate system based on the alignment result; obtain a second mapping relationship between the magnetic navigation coordinate system and the visual coordinate system based on the magnetic navigation coordinate system rotation information and the magnetic navigation coordinate system translation information.

[0131] In a specific implementation, a second point cloud corresponding to the second three-dimensional model can be obtained. Since the second point cloud is obtained based on the target object, the target object sampling points are also obtained based on the target object. There is a correspondence between the target object sampling points and some points in the second point cloud.

[0132] In this regard, the target object sampling points and the second point cloud can be registered to obtain corresponding registration results. In some embodiments, the target object sampling points and the second point cloud can be registered using the ICP algorithm. Specifically, multiple target object sampling points can be used as the third point cloud, and then the third point cloud and the second point cloud are registered. The specific registration process is the same or similar to the ICP registration process mentioned in the above embodiment, and will not be repeated here.

[0133] Then, the rotation information of the magnetic navigation coordinate system and the translation information of the magnetic navigation coordinate system transformed from the magnetic navigation coordinate system to the visual coordinate system can be obtained according to the registration result, and the rotation information of the magnetic navigation coordinate system and the translation information of the magnetic navigation coordinate system are used as the second mapping relationship. Subsequently, for each coordinate position in the magnetic navigation coordinate system acquired based on the magnetic sensor, the coordinate position can be rotated and translated according to the rotation information of the magnetic navigation coordinate system and the translation information of the magnetic navigation coordinate system to obtain the corresponding point in the visual coordinate system.

[0134] In this embodiment, by aligning the sampling points of the target object and the second point cloud, the rotation information and translation information of the magnetic navigation coordinate system transformed from the magnetic navigation coordinate system to the visual coordinate system can be accurately obtained, providing a reliable calculation basis for the subsequent mapping of the points in the magnetic navigation coordinate system to the visual coordinate system.

[0135] In one embodiment, Figure 5 As shown, registering the target object sampling points with the second point cloud may include the following steps:

[0136] S501, pre-register the target object sampling points and the second point cloud.

[0137] In some embodiments, the target object sampling point and the second point cloud may be registered multiple times, and a more accurate registration result may be selected by comparing the multiple registrations. For the sake of distinction, when multiple registrations are performed, each registration may be referred to as a pre-registration. In this step, the target object sampling point and the second point cloud may be pre-registered multiple times.

[0138] S502: Determine a first corresponding point of a target object sampling point in the visual coordinate system and a second corresponding point of the first corresponding point in the magnetic navigation coordinate system according to a candidate mapping relationship between the pre-registered magnetic navigation coordinate system and the visual coordinate system.

[0139] After each pre-registration, the candidate mapping relationship corresponding to this pre-registration can be obtained, and the candidate mapping relationship represents the way of converting from the magnetic navigation coordinate system to the visual coordinate system. Then, the corresponding points of the target sampling points in the visual coordinate system can be determined according to the candidate mapping relationship, that is, the pose of the target sampling points is transformed through the candidate mapping relationship, and the points obtained in the visual coordinate system are taken as corresponding points. For the convenience of distinction, the corresponding points obtained from the magnetic navigation coordinate system to the visual coordinate system according to the candidate mapping relationship are called the first corresponding points.

[0140] During the transformation process, due to the objective delay of the magnetic navigation device, such as the delay caused by data transmission and data processing, there may be a certain deviation between the position of the recorded target sampling point and the position corresponding to the actual sampled point, thereby affecting the accuracy of the registration result. In this regard, in this embodiment, after obtaining the first corresponding point, an inverse operation can be performed according to the candidate mapping relationship to determine the corresponding point of the first corresponding point in the magnetic navigation coordinate system. For the convenience of distinction, the corresponding point obtained according to the candidate mapping relationship and transformed from the visual coordinate system to the magnetic navigation coordinate system is called the second corresponding point.

[0141] S503: Determine accuracy information of the pre-registration correspondence according to the error between the second corresponding point and the target object sampling point.

[0142] If the registration accuracy is good, the second corresponding point and the corresponding target sampling point may be in the same position or have a small error in the magnetic navigation coordinate system. If the registration accuracy is poor, there may be a large error between the second corresponding point and the corresponding target sampling point. In this regard, in this step, the accuracy information of the pre-registration correspondence can be determined based on the error between the second corresponding point and the target sampling point. In some embodiments, the accuracy information can be the accuracy or the error size.

[0143] S504: Determine a registration result according to the candidate mapping relationship corresponding to the pre-registration whose accuracy information satisfies the accuracy condition.

[0144] Then, the accuracy information of each pre-registration can be compared to determine the pre-registration whose accuracy information meets the accuracy condition. For example, the pre-registration with the highest accuracy or the pre-registration with an accuracy exceeding a threshold can be determined as satisfying the accuracy condition, and the candidate mapping relationship corresponding to the pre-registration can be determined as the final registration result.

[0145] In this embodiment, by performing multiple pre-registrations and comparing the accuracy information of each pre-registration, the registration accuracy and reliability of mapping the magnetic navigation coordinate system to the visual coordinate system can be effectively improved in the presence of objective errors.

[0146] In one embodiment, in step S503, determining the accuracy information of the pre-registration correspondence according to the error between the second corresponding point and the target object sampling point may include the following steps:

[0147] For the target object sampling point, the error distance between the second corresponding point and the target object sampling point is obtained; and the accuracy information of the pre-registration corresponding is determined according to each error distance.

[0148] In a specific implementation, for each target sampling point, the first corresponding point corresponding to it can be determined according to the candidate mapping relationship obtained by pre-registration, and the first corresponding point can be reconverted into the second corresponding point of the magnetic navigation coordinate system, and then the error distance between the second corresponding point and the target sampling point can be obtained. Then, the accuracy information corresponding to this pre-registration can be determined by combining the error distances corresponding to each target sampling point. For example, the error distances can be summed or averaged, and the accuracy information can be obtained according to the processing results.

[0149] In one embodiment, multiple target sampling points can be divided into multiple point sets. The multiple point sets can be divided according to different trajectories during sampling. For example, each target sampling point corresponding to a line along which the target moves during sampling can be determined as a point set. For another example, each target sampling point corresponding to a circle along which the target moves during sampling can be determined as a point set. Then, the accuracy information can be determined according to the following method:

[0150]

[0151] Where e is the sum of the squares of the distance errors, and are the number of point sets and the number of target sampling points in each point set respectively, and dij is the distance from the second corresponding point i to the feature j corresponding to the target sampling point set, such as the distance from the second corresponding point to the line and the distance from the second corresponding point to the circle.

[0152] In this embodiment, by obtaining the error distance between the second corresponding point and the target object sampling point, the accuracy information of the pre-registration correspondence can be accurately quantified.

[0153] In order to enable those skilled in the art to better understand the above steps, the embodiment of the present application is illustrated below by using an example, but it should be understood that the embodiment of the present application is not limited to this.

[0154] like Figure 3 As shown, the magnetic navigation coordinate system and the CT coordinate system can be calibrated in advance, and a first three-dimensional model in the CT coordinate system can be reconstructed based on multiple preoperative CT images corresponding to the target object, and a corresponding second three-dimensional model can be determined in the visual coordinate system.

[0155] Then, on the one hand, for the target object to be operated on, a scalpel, surgical needle or saw equipped with a magnetic sensor can be used to sample the surface of the target object to obtain multiple target sampling points in the magnetic navigation coordinate system, and the magnetic navigation coordinate system is mapped to the visual coordinate system according to the registration results of the multiple target sampling points and the second three-dimensional model. On the other hand, the CT coordinate system can be mapped to the visual coordinate system based on the registration results of the first three-dimensional model and the second three-dimensional model. Subsequently, the corresponding tracking results can be displayed in the visual interface according to the intraoperative CT image and the coordinate position of the magnetic sensor during the operation.

[0156] It should be understood that, although the various steps in the flowcharts involved in the above-mentioned embodiments are displayed in sequence according to the indication of the arrows, these steps are not necessarily executed in sequence according to the order indicated by the arrows. Unless there is a clear explanation in this article, the execution of these steps does not have a strict order restriction, and these steps can be executed in other orders. Moreover, at least a part of the steps in the flowcharts involved in the above-mentioned embodiments can include multiple steps or multiple stages, and these steps or stages are not necessarily executed at the same time, but can be executed at different times, and the execution order of these steps or stages is not necessarily to be carried out in sequence, but can be executed in turn or alternately with other steps or at least a part of the steps or stages in other steps.

[0157] Based on the same inventive concept, the embodiment of the present application also provides a tracking device based on magnetic navigation for implementing the above-mentioned tracking method based on magnetic navigation. The implementation scheme for solving the problem provided by the device is similar to the implementation scheme recorded in the above-mentioned method, so the specific limitations in one or more embodiments of the tracking device based on magnetic navigation provided below can refer to the limitations of the tracking method based on magnetic navigation above, and will not be repeated here.

[0158] In an exemplary embodiment, Figure 6 As shown, a tracking device based on magnetic navigation is provided, comprising:

[0159] A first model acquisition module 601 is used to acquire a first three-dimensional model of the target object in a CT coordinate system;

[0160] A first mapping relationship acquisition module 602 is used to construct a second three-dimensional model corresponding to the first three-dimensional model in a visual coordinate system, and determine a first mapping relationship between the CT coordinate system and the visual coordinate system according to the first three-dimensional model and the second three-dimensional model;

[0161] A second mapping relationship acquisition module 603 is used to acquire a plurality of target object sampling points of the target object in the magnetic navigation coordinate system according to the movement trajectory of the surgical tool equipped with the magnetic sensor on the surface of the target object, and determine a second mapping relationship between the magnetic navigation coordinate system and the visual coordinate system according to the target object sampling points and the second three-dimensional model;

[0162] The tracking module 604 is used to display the second three-dimensional model of the target object in the visualization interface according to the first mapping relationship, and to display the position of the surgical tool provided with the magnetic sensor relative to the second three-dimensional model in the visualization interface according to the second mapping relationship.

[0163] In one embodiment, the second mapping relationship acquisition module 603 is used to:

[0164] Acquire a second point cloud corresponding to the second three-dimensional model;

[0165] Registering the target object sampling point and the second point cloud, and determining magnetic navigation coordinate system rotation information and magnetic navigation coordinate system translation information for transforming from the magnetic navigation coordinate system to the visual coordinate system according to the registration result;

[0166] A second mapping relationship between the magnetic navigation coordinate system and the visual coordinate system is obtained according to the rotation information of the magnetic navigation coordinate system and the translation information of the magnetic navigation coordinate system.

[0167] In one embodiment, the second mapping relationship acquisition module 603 is used to:

[0168] Pre-registering the target object sampling points and the second point cloud;

[0169] Determine, according to the candidate mapping relationship between the magnetic navigation coordinate system and the visual coordinate system obtained by the pre-registration, a first corresponding point of the target object sampling point in the visual coordinate system, and a second corresponding point of the first corresponding point in the magnetic navigation coordinate system;

[0170] Determining accuracy information of the pre-registration correspondence according to an error between the second corresponding point and the target object sampling point;

[0171] A registration result is determined according to the candidate mapping relationship corresponding to the pre-registration whose accuracy information satisfies the accuracy condition.

[0172] In one embodiment, the second mapping relationship acquisition module 603 is used to:

[0173] For the target object sampling point, obtaining an error distance between the second corresponding point and the target object sampling point;

[0174] According to each of the error distances, accuracy information corresponding to the pre-registration is determined.

[0175] In one embodiment, the first mapping relationship acquisition module 602 is used to:

[0176] Acquire a first point cloud corresponding to the first three-dimensional model and a second point cloud corresponding to the second three-dimensional model;

[0177] Registering the first point cloud and the second point cloud, and determining CT coordinate system rotation information and CT coordinate system translation information for transforming from the CT coordinate system to the visual coordinate system according to the registration result;

[0178] A first mapping relationship between the CT coordinate system and the visual coordinate system is obtained according to the CT coordinate system rotation information and the CT coordinate system translation information.

[0179] In one embodiment, the first model acquisition module 601 is used to:

[0180] Acquire multiple preoperative CT images corresponding to the target object;

[0181] For a plurality of visible points corresponding to the same spatial point in a plurality of the preoperative CT images, determining a reconstructed position of the spatial point in the CT coordinate system according to the visible point position and CT projection parameters of the visible point in each of the preoperative CT images;

[0182] According to the reconstructed position of each of the spatial points, a first three-dimensional model of the target object in the CT coordinate system is constructed.

[0183] Each module in the above-mentioned magnetic navigation-based tracking device can be implemented in whole or in part by software, hardware, or a combination thereof. Each of the above-mentioned modules can be embedded in or independent of a processor in a computer device in the form of hardware, or can be stored in a memory in a computer device in the form of software, so that the processor can call and execute operations corresponding to each of the above modules.

[0184] In an exemplary embodiment, a computer device is provided. The computer device may be a terminal, and its internal structure diagram may be as shown in FIG. Figure 7As shown. The computer device includes a processor, a memory, an input / output interface, a communication interface, a display unit and an input device. The processor, the memory and the input / output interface are connected through a system bus, and the communication interface, the display unit and the input device are connected to the system bus through the input / output interface. The processor of the computer device is used to provide computing and control capabilities. The memory of the computer device includes a non-volatile storage medium and an internal memory. The non-volatile storage medium stores an operating system and a computer program. The internal memory provides an environment for the operation of the operating system and the computer program in the non-volatile storage medium. The input / output interface of the computer device is used to exchange information between the processor and the external device. The communication interface of the computer device is used to communicate with an external terminal in a wired or wireless manner, and the wireless manner can be implemented through WIFI, a mobile cellular network, near field communication (NFC) or other technologies. When the computer program is executed by the processor, a tracking method based on magnetic navigation is implemented. The display unit of the computer device is used to form a visually visible picture, which can be a display screen, a projection device or a virtual reality imaging device. The display screen can be a liquid crystal display screen or an electronic ink display screen, and the input device of the computer device can be a touch layer covering the display screen, or a button, trackball or touchpad set on the computer device shell, or an external keyboard, touchpad or mouse.

[0185] Those skilled in the art will understand that Figure 7 The structure shown in the figure is only a block diagram of a part of the structure related to the solution of the present application, and does not constitute a limitation on the computer device to which the solution of the present application is applied. The specific computer device may include more or fewer components than those shown in the figure, or combine certain components, or have a different arrangement of components.

[0186] In one embodiment, a computer device is provided, including a memory and a processor, wherein a computer program is stored in the memory, and the processor implements the steps in the above-mentioned method embodiments when executing the computer program.

[0187] In one embodiment, a computer-readable storage medium is provided, on which a computer program is stored. When the computer program is executed by a processor, the steps in the above-mentioned method embodiments are implemented.

[0188] In one embodiment, a computer program product is provided, including a computer program, which implements the steps in the above method embodiments when executed by a processor.

[0189] It should be noted that the user 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, displayed data, etc.) involved in this application are all information and data authorized by the user or fully authorized by all parties, and the collection, use and processing of relevant data must comply with relevant regulations.

[0190] A person of ordinary skill in the art can understand that all or part of the processes in the above-mentioned embodiment method can be completed by instructing the relevant hardware through a computer program, and the computer program can be stored in a non-volatile computer-readable storage medium. When the computer program is executed, it can include the processes of the embodiments of the above-mentioned methods. Among them, any reference to the memory, database or other medium used in the embodiments provided in the present application can include at least one of non-volatile memory and volatile memory. Non-volatile memory can include read-only memory (ROM), magnetic tape, floppy disk, flash memory, optical memory, high-density embedded non-volatile memory, resistive random access memory (ReRAM), magnetic random access memory (MRAM), ferroelectric random access memory (FRAM), phase change memory (PCM), graphene memory, etc. Volatile memory can include random access memory (RAM) or external cache memory, etc. As an illustration and not limitation, RAM can be in various forms, such as static random access memory (SRAM) or dynamic random access memory (DRAM). The database involved in each embodiment provided in this application may include at least one of a relational database and a non-relational database. Non-relational databases may include distributed databases based on blockchains, etc., but are not limited to this. The processor involved in each embodiment provided in this application may be a general-purpose processor, a central processing unit, a graphics processor, a digital signal processor, a programmable logic device, a data processing logic device based on quantum computing, an artificial intelligence (AI) processor, etc., but are not limited to this.

[0191] The technical features of the above embodiments may be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this application.

[0192] The above-described embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the present application. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the present application shall be subject to the attached claims.

Claims

1. A tracking method based on magnetic navigation, characterized in that: The method comprises: Acquire a first three-dimensional model of the target object in the CT coordinate system; Constructing a second three-dimensional model corresponding to the first three-dimensional model in a visual coordinate system, and determining a first mapping relationship between the CT coordinate system and the visual coordinate system according to the first three-dimensional model and the second three-dimensional model; Acquire a plurality of target sampling points of the target in a magnetic navigation coordinate system according to a movement trajectory of a surgical tool equipped with a magnetic sensor on the surface of the target, and determine a second mapping relationship between the magnetic navigation coordinate system and the visual coordinate system according to the target sampling points and the second three-dimensional model; The second three-dimensional model of the target object is displayed in a visualization interface according to the first mapping relationship, and the position of the surgical tool provided with the magnetic sensor relative to the second three-dimensional model is displayed in the visualization interface according to the second mapping relationship.

2. The method according to claim 1, characterized in that The determining, according to the target object sampling point and the second three-dimensional model, a second mapping relationship between the magnetic navigation coordinate system and the visual coordinate system comprises: Acquire a second point cloud corresponding to the second three-dimensional model; Registering the target object sampling point and the second point cloud, and determining magnetic navigation coordinate system rotation information and magnetic navigation coordinate system translation information for transforming from the magnetic navigation coordinate system to the visual coordinate system according to the registration result; A second mapping relationship between the magnetic navigation coordinate system and the visual coordinate system is obtained according to the rotation information of the magnetic navigation coordinate system and the translation information of the magnetic navigation coordinate system.

3. The method according to claim 2, characterized in that The registering the target object sampling points and the second point cloud comprises: Pre-registering the target object sampling points and the second point cloud; Determine, according to the candidate mapping relationship between the magnetic navigation coordinate system and the visual coordinate system obtained by the pre-registration, a first corresponding point of the target object sampling point in the visual coordinate system, and a second corresponding point of the first corresponding point in the magnetic navigation coordinate system; Determining accuracy information of the pre-registration correspondence according to an error between the second corresponding point and the target object sampling point; A pre-registration satisfying the accuracy condition is determined according to the accuracy information, and a registration result is determined according to a candidate mapping relationship corresponding to the pre-registration satisfying the accuracy condition.

4. The method according to claim 3, characterized in that The determining the accuracy information of the pre-registration correspondence according to the error between the second corresponding point and the target object sampling point includes: For the target object sampling point, obtaining an error distance between the second corresponding point and the target object sampling point; According to each of the error distances, accuracy information corresponding to the pre-registration is determined.

5. The method according to claim 1, characterized in that The determining, according to the first three-dimensional model and the second three-dimensional model, a first mapping relationship between the CT coordinate system and the visual coordinate system includes: Acquire a first point cloud corresponding to the first three-dimensional model and a second point cloud corresponding to the second three-dimensional model; Registering the first point cloud and the second point cloud, and determining CT coordinate system rotation information and CT coordinate system translation information for transforming from the CT coordinate system to the visual coordinate system according to the registration result; A first mapping relationship between the CT coordinate system and the visual coordinate system is obtained according to the CT coordinate system rotation information and the CT coordinate system translation information.

6. The method according to claim 1, characterized in that The step of obtaining a first three-dimensional model of the target object in a CT coordinate system includes: Acquire multiple preoperative CT images corresponding to the target object; For a plurality of visible points corresponding to the same spatial point in a plurality of the preoperative CT images, determining a reconstructed position of the spatial point in the CT coordinate system according to the visible point position and CT projection parameters of the visible point in each of the preoperative CT images; According to the reconstructed position of each of the spatial points, a first three-dimensional model of the target object in the CT coordinate system is constructed.

7. A tracking device based on magnetic navigation, characterized in that: The device comprises: A first model acquisition module, used to acquire a first three-dimensional model of the target object in a CT coordinate system; a first mapping relationship acquisition module, configured to construct a second three-dimensional model corresponding to the first three-dimensional model in a visual coordinate system, and determine a first mapping relationship between the CT coordinate system and the visual coordinate system according to the first three-dimensional model and the second three-dimensional model; a second mapping relationship acquisition module, configured to acquire a plurality of target object sampling points of the target object in a magnetic navigation coordinate system according to a movement trajectory of a surgical tool equipped with a magnetic sensor on the surface of the target object, and determine a second mapping relationship between the magnetic navigation coordinate system and the visual coordinate system according to the target object sampling points and the second three-dimensional model; A tracking module is used to display the second three-dimensional model of the target object in a visualization interface according to the first mapping relationship, and to display the position of the surgical tool provided with the magnetic sensor relative to the second three-dimensional model in the visualization interface according to the second mapping relationship.

8. A computer device comprising a memory and a processor, wherein the memory stores a computer program, wherein: When the processor executes the computer program, the steps of the method according to any one of claims 1 to 6 are implemented.

9. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the steps of the method according to any one of claims 1 to 6 are implemented.

10. A computer program product, comprising a computer program, characterized in that When the computer program is executed by a processor, the steps of the method according to any one of claims 1 to 6 are implemented.

Images