Method, device and electronic device for obtaining reference mark position

Abstract

The present application provides a method, device and electronic device for obtaining the position of a reference marker point, which relates to the field of medical technology. The registration block includes a base plate and a reference array, the base plate includes a plurality of reference metal balls, and the reference array includes a plurality of positioning members, verification metal balls and grooves for probes. Obtain a first affine transformation matrix from the probe verification point coordinate system to the metal ball verification point coordinate system; obtain a second affine transformation matrix from the reference array coordinate system to the probe verification point coordinate system; obtain the coordinates of each reference metal ball in the metal ball verification point coordinate system based on the position of each reference metal ball and each verification metal ball in the obtained CT image; obtain the coordinates of each reference metal ball in the reference array coordinate system based on the first affine transformation matrix, the second affine transformation matrix and the coordinates of each reference metal ball in the metal ball verification point coordinate system. In this way, the accuracy of the relative position of the positioning members and the reference metal balls required for registering CT images can be improved.

Description

Technical Field

[0001] The present application relates to the field of medical technology, and in particular to a method, device and electronic device for obtaining the position of a reference marker point. Background Art

[0002] In image-guided surgery, a registration block is used to register the patient's CT image. The registration block includes a base plate and an optical reference array. A plurality of metal balls are embedded on the base plate as reference marking points. The optical reference array includes a plurality of reflective balls (or reflective sheets) that can be recognized by the positioning camera. The registration process is as follows: the registration block is fixed to the patient's target surgical area, and a CT scan of the registration block and the patient's target surgical area is taken to obtain a three-dimensional CT image, and the center set P1 of the metal ball image is obtained from the CT image; the positioning camera is used to capture the position of the reflective ball (or reflective sheet) on the optical reference array, and then the conversion relationship between the optical reference array coordinate system and the positioning unit coordinate system can be established; then, the relative position of the reflective ball (or reflective sheet) and the metal ball known in advance is combined to obtain the metal ball center set P2 in the positioning camera coordinate system; finally, by calculating the conversion relationship between the point set P1 and the point set P2, the conversion relationship between the positioning unit coordinate system and the CT image coordinate system is obtained, and the CT image registration is completed.

[0003] Therefore, it can be seen that the accuracy of the relative position of the reflective ball (or reflective sheet) and the metal ball affects the accuracy of CT image registration. However, the accuracy of the relative position of the reflective ball (or reflective sheet) and the metal ball currently used is low. Summary of the Invention

[0004] The embodiments of the present application provide a method, device, electronic device, and readable storage medium for obtaining the position of a reference marker, which can improve the accuracy of the relative position of a positioning member and a metal ball required for aligning CT images.

[0005] The embodiments of the present application can be implemented as follows:

[0006] In a first aspect, an embodiment of the present application provides a method for obtaining the position of a reference marker, which is applied to a positioning system. The positioning system includes a registration block, the registration block includes a base plate and a reference array, the base plate includes a plurality of reference metal balls, and the reference array includes a plurality of positioning members, a plurality of verification metal balls, and a plurality of grooves for a probe, wherein the number of the positioning members, verification metal balls, and grooves is greater than two. The method includes:

[0007] Obtaining a first affine transformation matrix from a probe verification point coordinate system to a metal ball verification point coordinate system, wherein the probe verification point coordinate system is a three-dimensional coordinate system established based on the plurality of grooves, and the metal ball verification point coordinate system is a three-dimensional coordinate system established based on the plurality of verification metal balls;

[0008] Obtaining a second affine transformation matrix from a reference array coordinate system to the probe verification point coordinate system, wherein the reference array coordinate system is a three-dimensional coordinate system established based on the plurality of positioning elements;

[0009] Obtaining coordinates of each reference metal ball in the metal ball verification point coordinate system according to positions of each reference metal ball and each verification metal ball in the registration block in the obtained CT image;

[0010] The coordinates of each reference metal ball in the reference array coordinate system are obtained according to the first affine transformation matrix, the second affine transformation matrix and the coordinates of each reference metal ball in the metal ball verification point coordinate system.

[0011] In a second aspect, an embodiment of the present application provides a device for obtaining the position of a reference mark point, which is applied to a positioning system. The positioning system includes a registration block, the registration block includes a base plate and a reference array, the base plate includes a plurality of reference metal balls, and the reference array includes a plurality of positioning members, a plurality of verification metal balls, and a plurality of grooves for a probe. The number of the positioning members, verification metal balls, and grooves is greater than two. The device includes:

[0012] a first matrix acquisition module, configured to obtain a first affine transformation matrix from a probe verification point coordinate system to a metal ball verification point coordinate system, wherein the probe verification point coordinate system is a three-dimensional coordinate system established based on the plurality of grooves, and the metal ball verification point coordinate system is a three-dimensional coordinate system established based on the plurality of verification metal balls;

[0013] a second matrix obtaining module, configured to obtain a second affine transformation matrix from a reference array coordinate system to the probe verification point coordinate system, wherein the reference array coordinate system is a three-dimensional coordinate system established based on the plurality of positioning elements;

[0014] a position obtaining module, configured to obtain the coordinates of each of the reference metal balls in the metal ball verification point coordinate system according to the positions of each of the reference metal balls and each of the verification metal balls in the registration block in the obtained CT image;

[0015] The conversion module is used to obtain the coordinates of each of the reference metal balls in the reference array coordinate system according to the first affine transformation matrix, the second affine transformation matrix and the coordinates of each of the reference metal balls in the metal ball verification point coordinate system.

[0016] In a third aspect, an embodiment of the present application provides an electronic device comprising a processor and a memory, wherein the memory stores machine-executable instructions that can be executed by the processor, and the processor can execute the machine-executable instructions to implement the method for obtaining the position of a reference marker point described in the aforementioned embodiment.

[0017] In a fourth aspect, an embodiment of the present application provides a readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the method for obtaining the position of a reference marker point as described in the aforementioned embodiment.

[0018] The method, device, electronic device and readable storage medium for obtaining the position of a reference mark point provided in the embodiments of the present application are applied to a positioning system, wherein the positioning system includes a registration block, the registration block includes a base plate and a reference array, the base plate includes a plurality of reference metal balls, the reference array includes a plurality of positioning parts, a plurality of verification metal balls and a plurality of grooves used by a probe, and the number of the positioning parts, verification metal balls and grooves is greater than 2. First, a first affine transformation matrix is obtained from the probe verification point coordinate system to the metal ball verification point coordinate system, and a second affine transformation matrix is obtained from the reference array coordinate system to the probe verification point coordinate system. The probe verification point coordinate system is a three-dimensional coordinate system established based on the multiple grooves, the metal ball verification point coordinate system is a three-dimensional coordinate system established based on the multiple verification metal balls, and the reference array coordinate system is a three-dimensional coordinate system established based on the multiple positioning members. Next, based on the positions of each reference metal ball and each verification metal ball in the registration block in the obtained CT image, the coordinates of each reference metal ball in the metal ball verification point coordinate system are obtained. Finally, based on the first affine transformation matrix, the second affine transformation matrix, and the coordinates of each reference metal ball in the metal ball verification point coordinate system, the coordinates of each reference metal ball in the reference array coordinate system are obtained. In this way, the position of the reference metal ball, which serves as a reference marker, in the reference array coordinate system can be calibrated, thereby improving the accuracy of CT image registration. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following is a brief introduction to the drawings required for use in the embodiments. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other relevant drawings can be obtained based on these drawings without creative work.

[0020] Figure 1 A schematic diagram of the structure of the registration block used in the prior art;

[0021] Figure 2 is a schematic diagram of the obtained CT image;

[0022] Figure 3 This is a schematic diagram of the use of an optical positioning camera;

[0023] Figure 4Schematic diagram of the deviation of the coordinate value of the center of the metal ball in the reference array coordinate system caused by the hardware structure of the existing registration block provided in the embodiment of the present application;

[0024] Figure 5 A schematic diagram of the structure of the registration block provided in an embodiment of the present application;

[0025] Figure 6 Schematic diagram of the probe coordinate system;

[0026] Figure 7 A schematic diagram of the registration block provided in an embodiment of the present application in the design engineering drawing image coordinate system;

[0027] Figure 8 A schematic diagram showing the use of a registration block and a positioning unit in conjunction with an embodiment of the present application;

[0028] Figure 9 A block diagram of an electronic device provided in an embodiment of the present application;

[0029] Figure 10 A schematic diagram of a flow chart of a method for obtaining a reference marker position according to an embodiment of the present application;

[0030] Figure 11 for Figure 10 Schematic diagram of the flow of sub-steps included in step S110;

[0031] Figure 12 Figure 11 A schematic flow chart of the sub-steps included in sub-step S112;

[0032] Figure 13 for Figure 10 Schematic diagram of the flow of sub-steps included in step S120;

[0033] Figure 14 for Figure 10 Schematic diagram of the flow of sub-steps included in step S130;

[0034] Figure 15 A block diagram of a device for acquiring a reference marker position according to an embodiment of the present application.

[0035] Icon: 100 - electronic device; 110 - memory; 120 - processor; 130 - communication unit; 200 - reference mark point position acquisition device; 210 - first matrix acquisition module; 220 - second matrix acquisition module; 230 - position acquisition module; 240 - conversion module. DETAILED DESCRIPTION

[0036] To make the objectives, technical solutions, and advantages of the embodiments of the present application more clear, the technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the accompanying drawings of the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Generally, the components of the embodiments of the present application described and shown in the drawings herein can be arranged and designed in various different configurations.

[0037] Therefore, the following detailed description of the embodiments of the present application provided in the accompanying drawings is not intended to limit the scope of the present application for protection, but merely represents selected embodiments of the present application. Based on the embodiments of the present application, all other embodiments obtained by those skilled in the art without making any creative efforts shall fall within the scope of protection of the present application.

[0038] It should be noted that relational terms such as "first" and "second" are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the terms "comprises," "comprising," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus comprising a series of elements includes not only those elements, but also other elements not explicitly listed, or elements inherent to such process, method, article, or apparatus. In the absence of further limitations, an element defined by the phrase "comprising a ..." does not exclude the presence of additional identical elements in the process, method, article, or apparatus comprising the element.

[0039] Currently, in image-guided surgery, Figure 1 The registration block shown is used to register the patient's CT image. The main part of the registration block is a polymeric material and is not visible in the CT image. Figure 1 As shown, the registration block includes a base plate and an optical reference array. The base plate is attached with more than 3 metal balls as reference marking points, and the optical reference array is installed with 3 reflective balls or reflective sheets that can be recognized by the positioning camera.

[0040] The registration principle is briefly described as follows:

[0041] 1. Fix the registration block to the patient's target surgical area (usually bone) in some way (such as with bone screws), and take a CT scan of the registration block and the patient's target surgical area. The resulting CT image can be as follows: Figure 2 As shown, the metal ball images on the registration block are in the same image coordinate system as the patient's bones. The set of centers of all metal ball images is denoted as P1. Point set P1 includes the coordinates of the centers of each metal ball in the CT image coordinate system, which is a three-dimensional coordinate system.

[0042] 2. Such as Figure 3 As shown, in image-guided surgery, the positioning camera can capture the position of the optical ball on the reference array of the registration block, thereby establishing a conversion relationship between the optical reference array coordinate system and the positioning camera coordinate system. At the same time, the distribution position of each metal ball on the registration block in the optical reference array coordinate system can be known in advance through design parameters. Therefore, the reference array of the positioning camera positioning registration block is the metal balls on the positioning registration block, and the centers of all metal balls in the positioning camera coordinate system constitute the point set P2. The point set P2 includes the coordinates of the centers of each metal ball in the positioning camera coordinate system, and the positioning camera coordinate system is a three-dimensional coordinate system.

[0043] 3. By calculating the transformation relationship between point set P2 and point set P1, the transformation relationship between the positioning camera coordinate system and the CT image coordinate system is obtained, completing CT image registration. The CT image data can be converted to the positioning camera coordinate system, and the bone image in the CT image is mapped to the patient's actual bone, thus enabling image-guided surgery.

[0044] From the brief description of the principle of using the above registration block, it can be seen that the coordinates of the center of each metal ball on the registration block and the relative position of the reflective balls on the reference array (that is, the coordinate values of the center of each metal ball in the reference array coordinate system) must be known, and the accuracy of their values directly affects the accuracy of image navigation.

[0045] Currently, the relative positions of the metal ball and the reference array reflective ball used in registration are generally obtained in the following two ways.

[0046] Method 1: Determine the coordinates of the metal ball's center in the optical reference array coordinate system from the design drawing of the registration block and use these coordinates for registration. This method is highly dependent on hardware machining accuracy, and there may be discrepancies between the geometric design values and the actual geometric values.

[0047] The hardware structure of the registration block causes the coordinate value of the center of the metal ball in the reference array coordinate system to be Figure 4 Three errors are shown:

[0048] 1. Such as Figure 4 As shown in Figure A, the reference array of the registration block and the base plate with embedded metal balls are two independent components, which are fixedly connected by a connecting mechanism. Manufacturing errors of this connecting mechanism cause the relative positions of the metal balls and reflective balls to deviate from the designed values.

[0049] 2. Such as Figure 4 As shown in Figure B, the manufacturing error of the reference array of the registration block causes the position of the reflective ball to deviate from the designed value.

[0050] 3. Such as Figure 4As shown in Figure C, the manufacturing error of the bottom plate of the registration block where the metal ball is embedded causes the position of the metal ball to deviate from the design value.

[0051] Method 2: Before using the registration block for CT image registration, an optical probe is used to collect the coordinates of the metal sphere's surface points on the registration block within the block's reference array. The sphere's center is then determined by fitting the sphere's surface, achieving pre-calibration. In some applications, the metal spheres are only 2-3 mm in diameter and embedded within the registration block, making it difficult to obtain their surface points using a probe. Collecting all the sphere's surface points is a tedious process.

[0052] In response to the above situation, the embodiments of the present application provide a method, device, electronic device and readable storage medium for obtaining the position of a reference mark point, which can obtain the coordinates of the reference metal ball in the base plate of the registration block in the reference array coordinate system of the registration block by calibration. Compared with the method of directly using the coordinate value of the center of the metal ball in the design drawing in the optical reference array coordinate system, the accuracy of the relative position of the positioning part required for aligning the CT image and the reference metal ball in the base plate can be improved, and there is no need to use an optical probe to collect the coordinate value of the surface point of the reference metal ball in the reference array of the registration block.

[0053] It is worth noting that the defects existing in the above solutions are the results obtained by the inventor after practice and careful research. Therefore, the discovery process of the above problems and the solutions proposed in the embodiments of this application below should be the contributions made by the inventor to this application during the application process.

[0054] The following describes some embodiments of the present application in detail with reference to the accompanying drawings. In the absence of conflict, the following embodiments and features therein may be combined with each other.

[0055] The embodiment of the present application provides a positioning system, which may include a registration block. Figure 5 As shown, the registration block may include a base plate and a reference array. A plurality of reference metal balls are provided on the base plate as reference marking points. The number of the reference metal balls is greater than 3, and the specific number can be set in accordance with actual needs. The plurality of reference metal balls can be set in an embedded manner on the base plate. The reference array includes a plurality of positioning members, the number of which is greater than 2, such as 3, and the positioning members can be identified by corresponding positioning units. The positioning members and the positioning unit can be specifically set in accordance with actual needs. For example, the positioning member is a reflective ball or a reflective sheet, and the positioning unit is an optical positioning camera.

[0056] The reference array may also include multiple verification metal balls and multiple grooves for use with the probe. The verification metal balls serve as metal ball verification points, and the grooves serve as probe verification points. The number of verification metal balls and grooves can both be greater than two and non-collinear, allowing for the subsequent establishment of a corresponding three-dimensional coordinate system.

[0057] As a possible implementation manner, the base plate and the reference array may be fixedly connected.

[0058] As another possible implementation, the base plate and the reference array may be connected using an adjustable connection mechanism so that the relative position between the base plate and the reference array is adjustable. Figure 5 As shown, the base plate and the reference array can rotate relative to each other about the line connecting the two. Thus, the relative position of the reference array and the base plate can be adjusted according to actual needs.

[0059] In current registration blocks, the relative position between the base plate and the optical reference array is fixed, meaning they are rigidly connected. Once the registration block is fixed to the patient, the optical reference array's position under the positioning camera cannot be changed. This results in limited mobility and can easily cause occlusion during surgery. The embodiments of the present application provide a registration block in which the relative position of the reference array and base plate is adjustable, thus avoiding this problem.

[0060] As a possible implementation, Figure 5 As shown, the alignment block of the embodiment of the present application has the following improvements compared with the current alignment block: 1. The reference array and the base plate inlaid with metal ball reference marking points adopt an adjustable connection mechanism, so that the relative position relationship between the reference array and the base plate can be adjusted according to actual needs; 2. Three new verification metal balls that are not located in the same straight line are added to the reference array as metal ball verification points; 3. Three new grooves that are not located in the same straight line are added to the reference array as probe verification points.

[0061] The probe can be used to obtain the coordinates of the corresponding position point in the probe coordinate system. Alternatively, an optical tracking probe can be used to obtain the coordinates. The structure of the optical tracking probe is as follows: Figure 6 As shown, three or four reflective balls are included to form a reference array. The origin of the probe coordinate system is located at the probe tip, and the coordinate axis directions are not specified. The probe can be calibrated first, for example by shaking the pen, so that the origin of its coordinate system is completely aligned with the tip.

[0062] like Figure 5 and Figure 7As shown, the registration block provided in the embodiments of the present application can establish multiple three-dimensional rectangular coordinate systems. For example, a reference array coordinate system can be established based on multiple positioning elements, a probe verification point coordinate system can be established based on multiple grooves, and a metal ball verification point coordinate system can be established based on multiple verification metal balls. The specific methods for establishing these three-dimensional coordinate systems can be set according to actual needs.

[0063] Optionally, as a possible implementation method, three points may be selected from the set multiple points, one of which is used as the origin of the coordinate system, and then the other two points are combined to establish a three-dimensional coordinate system.

[0064] like Figure 7 As shown in the figure, taking the metal ball verification point coordinate system as an example, the registration block includes three non-collinear verification metal balls: a, b, and c. The center of the verification metal ball a can be used as the origin of the metal ball verification point coordinate system, and the line connecting the centers of the verification metal balls a and b can be used as the X-axis. Then, combined with the positions of the verification metal balls b and c, the Y-axis and Z-axis can be determined to establish the metal ball verification point coordinate system.

[0065] It is understood that a three-dimensional coordinate system can be established based on three points in other ways, or based on a number greater than three points in other ways. The method for establishing a three-dimensional coordinate system can be set according to actual requirements and is not specifically limited here or below. For ease of illustration, the following detailed description of how to establish a three-dimensional coordinate system uses the above-mentioned method of using the center of the verification metal ball a as the origin, the line connecting the centers of the verification metal balls a and b as the X-axis, and then determining the Y-axis and Z-axis based on the X-axis to describe how to establish the corresponding three-dimensional coordinate system.

[0066] When designing the registration block in the engineering software, a three-dimensional rectangular coordinate system can be established in the virtual image space as the design engineering drawing image coordinate system for use in determining certain positions.

[0067] like Figure 8 As shown, the positioning unit can be used to identify the positioning members and other identifiable elements in the registration block, and the coordinates of the positioning members and other elements in the positioning unit coordinate system can be obtained. The positioning unit coordinate system is a coordinate system determined according to the positioning unit.

[0068] The above-mentioned positioning system may include a registration block, a positioning unit and a probe, and the coordinates of the reference metal ball in the system in the reference array coordinate system may be obtained using the reference mark point position acquisition method provided in the embodiment of the present application.

[0069] Please refer to Figure 9 , Figure 9This is a block diagram of an electronic device 100 provided in an embodiment of the present application. The electronic device 100 may be, but is not limited to, a computer, a server, or the like. The electronic device 100 includes a memory 110, a processor 120, and a communication unit 130. The memory 110, the processor 120, and the communication unit 130 are electrically connected to each other, directly or indirectly, to enable data transmission or exchange. For example, these components may be electrically connected to each other via one or more communication buses or signal lines.

[0070] The memory 110 is used to store programs or data. The memory 110 may be, but is not limited to, a random access memory (RAM), a read-only memory (ROM), a programmable read-only memory (PROM), an erasable programmable read-only memory (EPROM), an electrically erasable programmable read-only memory (EEPROM), etc.

[0071] The processor 120 is configured to read / write data or programs stored in the memory 110 and execute corresponding functions. For example, the memory 110 stores a fiducial marker location acquisition device 200, which includes at least one software function module stored in the memory 110 in the form of software or firmware. By running the software programs and modules stored in the memory 110, such as the fiducial marker location acquisition device 200 in the embodiments of the present application, the processor 120 executes various functional applications and data processing, thereby implementing the fiducial marker location acquisition method in the embodiments of the present application.

[0072] The communication unit 130 is used to establish a communication connection between the electronic device 100 and other communication terminals through a network, and to send and receive data through the network.

[0073] It should be understood that Figure 9 The structure shown is only a schematic diagram of the structure of the electronic device 100. The electronic device 100 may also include Figure 9 More or fewer components than shown, or with Figure 9 Different configurations shown. Figure 9 Each component shown in the figure can be implemented by hardware, software or a combination thereof.

[0074] Please refer to Figure 10 , Figure 10 A flow chart of a method for obtaining the position of a reference marker point provided in an embodiment of the present application. The method can be executed by the above-mentioned electronic device 100. The specific process of the method for obtaining the position of a reference marker point is described in detail below. The method is applied to a positioning system, the positioning system includes a registration block, the registration block includes a base plate and a reference array, the base plate includes a plurality of reference metal balls, the reference array includes a plurality of positioning members, a plurality of verification metal balls and a plurality of grooves used by the probe, and the number of the positioning members, verification metal balls and grooves is greater than 2. In this embodiment, the method may include steps S110 to S140.

[0075] Step S110 , obtaining a first affine transformation matrix from the probe verification point coordinate system to the metal ball verification point coordinate system.

[0076] The probe verification point coordinate system is a three-dimensional coordinate system established based on the multiple grooves. The metal ball verification point coordinate system is a three-dimensional coordinate system established based on the multiple verification metal balls. The first affine transformation matrix can be obtained based on the coordinates of each groove and each verification metal ball in the same three-dimensional coordinate system. The first affine transformation matrix can also be obtained by other methods, which are not specifically limited here.

[0077] Step S120 , obtaining a second affine transformation matrix from the reference array coordinate system to the probe verification point coordinate system.

[0078] The reference array coordinate system is a three-dimensional coordinate system established based on the multiple positioning elements. Alternatively, each groove may be probed using a probe, and a positioning device capable of detecting the positions of the positioning elements and probe in the reference array may be used to obtain coordinates in the positioning device coordinate system, thereby obtaining the second affine transformation matrix. The second affine transformation matrix may also be obtained using other methods, which are not specifically limited here.

[0079] Step S130 , obtaining the coordinates of each reference metal ball in the metal ball verification point coordinate system according to the positions of each reference metal ball and each verification metal ball in the registration block in the obtained CT image.

[0080] The registration block is fixed to the patient, and a CT scan is performed to obtain a CT image. Based on the CT image, the coordinates of each reference metal ball and each verification metal ball in the registration block in the CT image coordinate system of the CT image can be obtained. The CT image coordinate system is a three-dimensional rectangular coordinate system. Based on the coordinates of the verification metal balls in the CT image coordinate system, a conversion relationship between the metal ball verification point coordinate system and the CT image coordinate system can be established, thereby obtaining the coordinates of each reference metal ball in the metal ball verification point coordinate system.

[0081] Step S140 , obtaining the coordinates of each reference metal ball in the reference array coordinate system according to the first affine transformation matrix, the second affine transformation matrix and the coordinates of each reference metal ball in the metal ball verification point coordinate system.

[0082] The coordinates of each of the reference metal balls in the metal ball verification point coordinate system can be processed based on the first affine transformation matrix and the second affine transformation matrix, thereby converting the coordinates into the reference array coordinate system.

[0083] In this way, the position of the reference metal ball serving as the reference mark point in the reference array coordinate system can be calibrated, thereby improving the accuracy of CT image registration.

[0084] As a possible implementation, Figure 11 The first affine transformation matrix is obtained in the manner shown. Figure 11 , Figure 11 for Figure 10 Schematic diagram of the flow of sub-steps included in step S110. In this embodiment, step S110 may include sub-steps S111 to S114.

[0085] Sub-step S111 , obtaining the coordinates of the center of each verification metal ball and the coordinates of each groove in the design engineering drawing image coordinate system.

[0086] The design engineering drawing image coordinate system F0 is a three-dimensional coordinate system in the virtual image space. This design engineering drawing image coordinate system F0 can be established during the design phase of the registration block, and its origin can be anywhere in the virtual image space. In the engineering software, the reference array and the base plate can be combined at any angle to obtain the coordinates of the center of each verification metal ball and each groove in the design engineering drawing image coordinate system F0.

[0087] like Figure 7 As shown, there are grooves I, II, and III. The coordinates of grooves I, II, and III in the design engineering drawing image coordinate system F0 can be recorded as p I , p II , p III ; There are verification metal balls a, b, c, and the coordinates of the center of the verification metal balls in the design engineering drawing image coordinate system F0 can be recorded as p a 、p b 、p c .

[0088] The coordinates of the center of each verification metal ball and the coordinates of each groove in the design engineering drawing image coordinate system can be obtained and saved in the design stage, and then read from the saved data when needed.

[0089] Sub-step S112, obtaining a third affine transformation matrix from the design engineering drawing image coordinate system to the metal ball verification point coordinate system according to the sphere center coordinates of each verification metal ball in the design engineering drawing image coordinate system.

[0090] When the coordinates of the center of each verification metal ball in the design engineering drawing image coordinate system F0 are obtained, the metal ball verification point coordinate system F1 can be established based on the coordinates of the center of each verification metal ball in the design engineering drawing image coordinate system F0. Furthermore, based on the coordinates of the center of each verification metal ball in the design engineering drawing image coordinate system F0 and the coordinates in the metal ball verification point coordinate system F1, a third affine transformation matrix T from the design engineering drawing image coordinate system F0 to the metal ball verification point coordinate system F1 can be obtained. 01 Alternatively, in the case of the metal ball verification point coordinate system F1, the third affine transformation matrix T is obtained by other means. 01 .

[0091] As a possible example, the metal ball verification point coordinate system is established based on the three verification metal balls, which can be Figure 12 The third affine transformation matrix T is obtained in the manner shown 01 Please refer to Figure 12 , Figure 12 Figure 11 Flowchart of sub-steps included in sub-step S112. In this embodiment, sub-step S112 may include sub-steps S1121 to S1124.

[0092] In sub-step S1121, the center of one of the verification metal balls is used as the origin of the metal ball verification point coordinate system, and the X-axis direction vector of the metal ball verification point coordinate system is calculated based on the coordinates of the center of the verification metal ball where the origin is located and the coordinates of the center of the other verification metal ball.

[0093] Sub-step S1122, calculating the Y-axis direction vector of the metal ball verification point coordinate system based on the center coordinates of the verification metal ball where the origin is located, the center coordinates of the remaining verification metal ball and the X-axis direction vector of the metal ball verification point coordinate system.

[0094] Sub-step S1123, calculating the Z-axis direction vector of the metal ball verification point coordinate system according to the X-axis direction vector and the Y-axis direction vector of the metal ball verification point coordinate system.

[0095] Sub-step S1124, obtains the third affine transformation matrix based on the X-axis direction vector, Y-axis direction vector, Z-axis direction vector of the metal ball verification point coordinate system, and the coordinates of the origin of the metal ball verification point coordinate system in the design engineering drawing image coordinate system.

[0096] The following example describes how to obtain the third affine transformation matrix T 01 The third affine transformation matrix T 01 Used to represent rotation and translation.

[0097] like Figure 7 As shown, the metal ball verification point coordinate system is established based on the three verification metal balls a, b, and c.

[0098] In the design engineering drawing image coordinate system F0, the origin of the metal ball verification point coordinate system F1 is located at the center p of the verification metal ball a. a (x a ,y a ,z a ), the calculation method of the axis direction vector of the metal ball verification point coordinate system F1 is as follows:

[0099]

[0100] Among them, (r 00 ,r 10 ,r 20 )express The vector of , and so on.

[0101] Therefore, the third affine transformation matrix T from the design engineering drawing image coordinate system F0 to the metal ball verification point coordinate system F1 is 01 It can be expressed as:

[0102]

[0103] Sub-step S113 , obtaining a fourth affine transformation matrix from the design engineering drawing image coordinate system to the probe verification point coordinate system according to the coordinates of each groove in the design engineering drawing image coordinate system.

[0104] The implementation method of sub-step S113 is similar to that of sub-step S112, and the relevant description can refer to the above description.

[0105] The following takes the establishment of the probe verification point coordinate system F2 based on three grooves as an example to introduce how to obtain the fourth affine transformation matrix T 02 .

[0106] like Figure 7 As shown, the probe verification point coordinate system F2 is established based on three grooves I, II, and III.

[0107] The origin of the probe verification point coordinate system F2 is located at the groove I. In the design engineering drawing image coordinate system F0, the coordinates of the groove I are p I (x I ,yI , z I ), the direction vectors of each axis of the probe verification point coordinate system F2 are calculated as follows:

[0108]

[0109] Therefore, the fourth affine transformation matrix T from the design engineering drawing image coordinate system F0 to the probe verification point coordinate system F2 is 02 It can be expressed as:

[0110]

[0111] Sub-step S114: Calculate the first affine transformation matrix according to the third affine transformation matrix and the fourth affine transformation matrix.

[0112] The first affine transformation matrix T 21 T 21 =T 02 -1 ·T 01 .

[0113] Optionally, the groove and the verification metal ball can be integrally formed, so as to ensure that the error between the first affine transformation matrix obtained in the above manner and the first affine transformation matrix corresponding to the actual registration block manufactured can be ignored.

[0114] Optionally, when the above-mentioned registration block is used for the first time, the first affine transformation matrix can be obtained through sub-steps S111 to S114; when the above-mentioned registration block is not used for the first time, the first affine transformation matrix calculated for the first time can be directly obtained, so that the first affine transformation matrix can be quickly obtained.

[0115] In this embodiment, the positioning system further includes a positioning unit, which is used to track the probe and the positioning member. Figure 8 As shown, the positioning unit determines a positioning unit coordinate system, and the probe determines a probe coordinate system. Both the positioning unit coordinate system and the probe coordinate system are three-dimensional rectangular coordinate systems. Figure 13 The second affine transformation matrix is obtained in the manner shown. Figure 13 , Figure 13 for Figure 10 Schematic diagram of the flow of sub-steps included in step S120. In this embodiment, step S120 may include sub-steps S121 to S124.

[0116] In sub-step S121 , for each groove, a fifth affine transformation matrix from the positioning unit coordinate system corresponding to the groove to the probe coordinate system and a sixth affine transformation matrix from the positioning unit coordinate system corresponding to the groove to the reference array coordinate system are obtained.

[0117] As a possible implementation method, when the positioning unit can see the positioning elements of the probe and the reference array at the same time, the probe tip can be placed at each groove in turn to obtain the coordinates of the positioning element and the groove in the positioning unit coordinate system from the positioning unit coordinate system to the probe coordinate system F corresponding to each groove. p A fifth affine transformation matrix, and a sixth affine transformation matrix from the positioning unit coordinate system corresponding to each groove to the reference array coordinate system F3.

[0118] like Figure 8 As shown, the probe tip can be placed in grooves I, II, and III in sequence, and the positioning unit is used to track the probe and the positioning member, thereby obtaining and recording the following information in sequence: When the probe tip is located at groove I, the positioning unit coordinate system is converted to the probe coordinate system F p The fifth affine transformation matrix T1 of the positioning unit coordinate system to the reference array coordinate system F3, the sixth affine transformation matrix T1' of the positioning unit coordinate system to the reference array coordinate system F3; when the probe tip is located at the groove II, the positioning unit coordinate system to the probe coordinate system F p The fifth affine transformation matrix T2 of the positioning unit coordinate system to the reference array coordinate system F3, the sixth affine transformation matrix T2' of the positioning unit coordinate system to the reference array coordinate system F3; when the probe tip is located at the groove III, the positioning unit coordinate system to the probe coordinate system F p The fifth affine transformation matrix T3 of the positioning unit coordinate system is converted to the sixth affine transformation matrix T3' of the reference array coordinate system F3.

[0119] Optionally, obtaining the fifth and sixth affine transformation matrices by placing the probe can be performed preoperatively or during surgery. To improve operability, in this embodiment, preoperatively, the probe is sequentially placed at each groove to obtain the corresponding fifth and sixth affine transformation matrices. This avoids tedious probe acquisition operations during surgery.

[0120] In sub-step S122 , for each groove, according to the fifth affine transformation matrix and the sixth affine transformation matrix corresponding to the groove, a sixth affine transformation matrix from the reference array coordinate system to the probe coordinate system is calculated.

[0121] Continuing with the above example, when the fifth and sixth affine transformation matrices corresponding to grooves I, II, and III are obtained, the seventh affine transformation matrix corresponding to grooves I, II, and III can be calculated. The calculation method of the seventh affine transformation matrix is:

[0122] T 3pI =(T1') -1 T1,

[0123] T 3pII =(T2') -1 T2,

[0124] T 3pIII =(T3') -1 T3

[0125] Among them, T 3pI The reference array coordinate system F3 corresponding to the groove I is represented by the probe coordinate system F p The seventh affine transformation matrix, T 3pII Indicates the reference array coordinate system F3 corresponding to groove II to the probe coordinate system F p The seventh affine transformation matrix, T 3pIII Indicates the reference array coordinate system F3 corresponding to groove III to the probe coordinate system F p The seventh affine transformation matrix.

[0126] Sub-step S123 , obtaining the coordinates of each of the grooves in the reference array coordinate system according to the seventh affine transformation matrix corresponding to each of the grooves.

[0127] Sub-step S124: obtaining the second affine transformation matrix according to the coordinates of each groove in the reference array coordinate system.

[0128] As mentioned above, the first three rows of the last column of the affine transformation matrix represent the coordinates of the origin of one coordinate system in another coordinate system. Therefore, when the seventh affine transformation matrix corresponding to each groove is obtained, the coordinates of each groove in the reference array coordinate system F3 can be obtained, and then the probe verification point coordinate system F2 can be established. Afterwards, the second affine transformation matrix T from the reference array coordinate system F3 to the probe verification point coordinate system F2 can be calculated based on the coordinates of each groove in the reference array coordinate system F3 and the coordinates in the probe verification point coordinate system F2. 32 .

[0129] For example, following the above example, if there are three grooves I, II, and III, the second affine transformation matrix T can be obtained by the following method: 32 .

[0130] T[i,j] represents the element in the i-th row and j-th column of the matrix T. In the reference array coordinate system F3, the coordinate values p' of grooves I, II, and III are I 、p' II 、p' III It can be expressed as:

[0131]

[0132] In the reference array coordinate system F3, the origin of the probe verification point coordinate system F2 is located at p' I , the nominal calculation method of the axis direction vector of the probe verification point coordinate system F2 is as follows:

[0133]

[0134] Therefore, the second affine transformation matrix T from the reference array coordinate system F3 to the probe verification point coordinate system F2 is 32 It can be expressed as:

[0135]

[0136] In this embodiment, the relative position between the base plate and the reference array is adjustable. The relative positions between the base plate and the reference array can be the same or different during the preoperative phase and when the CT image is acquired. The reference array can be adjusted based on actual needs (e.g., to avoid obstruction), and its intraoperative position can be calibrated after acquiring the coordinates of the verification metal sphere in the CT image.

[0137] Please refer to Figure 14 , Figure 14 for Figure 10 Schematic diagram of the flow of sub-steps included in step S130. In this embodiment, step S130 may include sub-steps S131 to S133.

[0138] Sub-step S131 , obtaining the center coordinates of each verification metal ball and the center coordinates of each reference metal ball in the CT image coordinate system.

[0139] Sub-step S132 , obtaining an eighth affine transformation matrix from the CT image coordinate system to the metal verification point coordinate system according to the coordinates of the centers of the verification metal balls in the CT image coordinate system.

[0140] Sub-step S133 , calculating the center coordinates of each reference metal ball in the metal verification point coordinate system according to the center coordinates of each reference metal ball in the CT image coordinate system and the eighth affine transformation matrix.

[0141] In this embodiment, during the operation, the registration block and the patient can be photographed together with CT to obtain a CT image. Then, in the CT image coordinate system F4, each verification metal ball and each reference metal ball can be manually selected in sequence, or the verification metal ball and the reference metal ball in the CT image can be determined by automatic recognition or other methods, thereby obtaining the coordinates of each verification metal ball and each reference metal ball in the CT image coordinate system F4. If the setting method of the reference metal ball and the verification metal ball in the registration block is as follows Figure 8 As shown, the coordinates of each verification metal ball and each reference metal ball in the CT image coordinate system F4 can be recorded in the homogeneous form as p1, p2, p3, p4, p5, p' a , p' b , p' c .

[0142] In the CT image coordinate system F4, the origin of the metal ball verification point coordinate system F1 is the sphere center coordinate p' of the verification metal ball a image. a (x' a ,y' a ,z' a ), the calculation method of the axis direction vectors of the metal ball verification point coordinate system F1 at this time is as follows:

[0143]

[0144] Then the eighth affine transformation matrix T from the CT image coordinate system F4 to the metal verification point coordinate system F1 is 41 It can be expressed as:

[0145]

[0146] In obtaining the eighth affine transformation matrix T 41 In the case of 41 The coordinates of each reference metal ball in the metal ball verification point coordinate system F1 are obtained as follows: i '=(T 41 ) -1 ·p i ,(i=1,2,3,4,5).

[0147] For the reference metal ball i (i = 1, 2, 3, 4, 5), calculate its homogeneous coordinate value pi" under the reference array F3 as: i ”=T 32 ·T 21 ·p i ', (i=1, 2, 3, 4, 5). In this way, the coordinate value of each reference metal ball in the reference array coordinate system is obtained, that is, the relative position relationship between each reference metal ball and the positioning member is obtained.

[0148] The calibration scheme provided in the embodiments of the present application employs a method of placing a verification metal ball and a groove on a reference array. The groove is first used to calibrate the relative position of the verification metal ball and the reference array. The center of the CT metal ball image is then captured to calibrate the relative position of the reference metal ball and the verification metal ball. Finally, these two sets of relationships are connected in series to obtain the required coordinate values of the reference metal ball within the optical reference array. Furthermore, since the verification metal ball and the groove are located on an integrally formed reference array component, the error in their relative positional relationship is negligible. Therefore, the relative positional relationship between the verification metal ball and the groove can be determined using the design engineering drawing image coordinate system.

[0149] The above-mentioned solution provided by the embodiment of the present application can avoid the influence of the three forms of manufacturing errors mentioned above. In addition, by setting the relative position relationship between the reference array and the base plate embedded with the reference metal ball, there is no need to lock it, so that the position of the reference array can be adjusted according to actual needs. For example, the position of the reference array can be adjusted to avoid being blocked, which can improve the visibility of the reference array under the positioning unit. Its intraoperative posture can be calibrated after the coordinates of the verification metal ball in the CT image are collected. The image collection of the verification metal ball is carried out together with the image collection of the reference metal ball during the operation. Collecting the position of the reference metal ball in the CT image is an operation originally required for the operation, so this set of calibration methods has almost no impact on the original intraoperative operation process during the operation.

[0150] In order to execute the corresponding steps in the above embodiments and various possible methods, an implementation method of a reference mark point position acquisition device 200 is given below. Optionally, the reference mark point position acquisition device 200 can adopt the above Figure 9 The device structure of the electronic device 100 is shown in FIG. Figure 15 , Figure 15 This is a block diagram of a device 200 for obtaining a reference marker position according to an embodiment of the present application. It should be noted that the basic principles and technical effects of the device 200 for obtaining a reference marker position according to this embodiment are the same as those of the aforementioned embodiments. For the sake of brevity, any details not mentioned in this embodiment may be referred to the corresponding contents of the aforementioned embodiments.

[0151] In this embodiment, the device 200 for acquiring the position of a fiducial marker can be applied to a positioning system. The positioning system includes a registration block, which includes a base plate and a reference array. The base plate includes multiple reference metal balls. The reference array includes multiple positioning elements, multiple verification metal balls, and multiple grooves for use with a probe. The number of positioning elements, verification metal balls, and grooves is greater than two. The device 200 for acquiring the position of a fiducial marker can include a first matrix acquisition module 210, a second matrix acquisition module 220, a position acquisition module 230, and a conversion module 240.

[0152] The first matrix acquisition module 210 is configured to obtain a first affine transformation matrix from a probe verification point coordinate system to a metal ball verification point coordinate system, wherein the probe verification point coordinate system is a three-dimensional coordinate system established based on the plurality of grooves, and the metal ball verification point coordinate system is a three-dimensional coordinate system established based on the plurality of verification metal balls.

[0153] The second matrix obtaining module 220 is used to obtain a second affine transformation matrix from a reference array coordinate system to the probe verification point coordinate system, wherein the reference array coordinate system is a three-dimensional coordinate system established based on the plurality of positioning elements.

[0154] The position acquisition module 230 is configured to obtain the coordinates of each reference metal ball in the metal ball verification point coordinate system according to the positions of each reference metal ball and each verification metal ball in the registration block in the obtained CT image.

[0155] The conversion module 240 is used to obtain the coordinates of each of the reference metal balls in the reference array coordinate system according to the first affine transformation matrix, the second affine transformation matrix and the coordinates of each of the reference metal balls in the metal ball verification point coordinate system.

[0156] Optionally, the above modules can be stored in the form of software or firmware. Figure 9 The memory 110 shown in FIG. 110 or the operating system (OS) of the electronic device 100 may be fixed and may be used by Figure 1 Meanwhile, the data, program codes, etc. required to execute the above modules may be stored in the memory 110.

[0157] An embodiment of the present application further provides a readable storage medium having a computer program stored thereon, and when the computer program is executed by a processor, the method for obtaining the position of a reference marker point is implemented.

[0158] To summarize, the embodiments of the present application provide a method, device, electronic device, and readable storage medium for obtaining the position of a reference marker point, which are applied to a positioning system. The positioning system includes a registration block, the registration block includes a base plate and a reference array, the base plate includes multiple reference metal balls, the reference array includes multiple positioning parts, multiple verification metal balls, and multiple grooves used by probes, and the number of the positioning parts, verification metal balls, and grooves is greater than 2. First, a first affine transformation matrix is obtained from the probe verification point coordinate system to the metal ball verification point coordinate system, and a second affine transformation matrix is obtained from the reference array coordinate system to the probe verification point coordinate system. The probe verification point coordinate system is a three-dimensional coordinate system established based on the multiple grooves, the metal ball verification point coordinate system is a three-dimensional coordinate system established based on the multiple verification metal balls, and the reference array coordinate system is a three-dimensional coordinate system established based on the multiple positioning members. Next, based on the positions of each reference metal ball and each verification metal ball in the registration block in the obtained CT image, the coordinates of each reference metal ball in the metal ball verification point coordinate system are obtained. Finally, based on the first affine transformation matrix, the second affine transformation matrix, and the coordinates of each reference metal ball in the metal ball verification point coordinate system, the coordinates of each reference metal ball in the reference array coordinate system are obtained. In this way, the position of the reference metal ball, which serves as a reference marker, in the reference array coordinate system can be calibrated, thereby improving the accuracy of CT image registration.

[0159] In the several embodiments provided in this application, it should be understood that the disclosed devices and methods can also be implemented in other ways. The device embodiments described above are merely illustrative. For example, the flowcharts and block diagrams in the accompanying drawings show the possible architectures, functions and operations of the devices, methods and computer program products according to the multiple embodiments of the present application. In this regard, each box in the flowchart or block diagram can represent a module, a program segment or a part of the code, and the module, program segment or a part of the code contains one or more executable instructions for implementing the specified logical functions. It should also be noted that in some alternative implementations, the functions marked in the box can also occur in an order different from that marked in the accompanying drawings. For example, two consecutive boxes can actually be executed substantially in parallel, and they can sometimes be executed in the opposite order, depending on the functions involved. It should also be noted that each box in the block diagram and / or flowchart, and the combination of boxes in the block diagram and / or flowchart, can be implemented using a dedicated hardware-based system that performs the specified function or action, or can be implemented using a combination of dedicated hardware and computer instructions.

[0160] In addition, the functional modules in each embodiment of the present application can be integrated together to form an independent part, or each module can exist independently, or two or more modules can be integrated to form an independent part.

[0161] If the functions are implemented in the form of software function modules and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present application, or the part that contributes to the prior art or the part of the technical solution, can be embodied in the form of a software product. The computer software product is stored in a storage medium and includes several instructions for enabling a computer device (which can be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the method described in each embodiment of the present application. The aforementioned storage medium includes various media that can store program codes, such as a USB flash drive, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk or an optical disk.

[0162] The above description is merely an optional embodiment of the present application and is not intended to limit the present application. Various modifications and variations are possible for those skilled in the art. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present application shall be included within the scope of protection of the present application.

Claims

1. A method for obtaining a reference mark point position, characterized in that: The method is applied to a positioning system, wherein the positioning system includes a registration block, the registration block includes a base plate and a reference array, the base plate includes a plurality of reference metal balls, the reference array includes a plurality of positioning members, a plurality of verification metal balls, and a plurality of grooves for a probe, wherein the number of the positioning members, verification metal balls, and grooves is greater than two, and the method includes: Obtaining a first affine transformation matrix from a probe verification point coordinate system to a metal ball verification point coordinate system, wherein the probe verification point coordinate system is a three-dimensional coordinate system established based on the plurality of grooves, and the metal ball verification point coordinate system is a three-dimensional coordinate system established based on the plurality of verification metal balls; Obtaining a second affine transformation matrix from a reference array coordinate system to the probe verification point coordinate system, wherein the reference array coordinate system is a three-dimensional coordinate system established based on the plurality of positioning elements; Obtaining coordinates of each reference metal ball in the metal ball verification point coordinate system according to positions of each reference metal ball and each verification metal ball in the registration block in the obtained CT image; The coordinates of each reference metal ball in the reference array coordinate system are obtained according to the first affine transformation matrix, the second affine transformation matrix and the coordinates of each reference metal ball in the metal ball verification point coordinate system.

2. The method according to claim 1, characterized in that The groove and the verification metal ball are integrally formed, and the first affine transformation matrix from the probe verification point coordinate system to the metal ball verification point coordinate system is obtained, including: Obtaining the coordinates of the center of each verification metal ball and the coordinates of each groove in the design engineering drawing image coordinate system, wherein the design engineering drawing image coordinate system is a three-dimensional coordinate system; Obtaining a third affine transformation matrix from the design engineering drawing image coordinate system to the metal ball verification point coordinate system according to the sphere center coordinates of each verification metal ball in the design engineering drawing image coordinate system; Obtaining a fourth affine transformation matrix from the design engineering drawing image coordinate system to the probe verification point coordinate system according to the coordinates of each of the grooves in the design engineering drawing image coordinate system; The first affine transformation matrix is calculated based on the third affine transformation matrix and the fourth affine transformation matrix.

3. The method according to claim 2, characterized in that The metal ball verification point coordinate system is established based on the three verification metal balls, and the third affine transformation matrix from the design engineering drawing image coordinate system to the metal ball verification point coordinate system is obtained based on the center coordinates of each verification metal ball in the design engineering drawing image coordinate system, including: The center of one of the verification metal balls is used as the origin of the metal ball verification point coordinate system, and the X-axis direction vector of the metal ball verification point coordinate system is calculated based on the coordinates of the center of the verification metal ball where the origin is located and the coordinates of the center of the other verification metal ball; Calculate the Y-axis direction vector of the metal ball verification point coordinate system based on the coordinates of the center of the verification metal ball where the origin is located, the coordinates of the center of the remaining verification metal ball, and the X-axis direction vector of the metal ball verification point coordinate system; Calculate the Z-axis direction vector of the metal ball verification point coordinate system according to the X-axis direction vector and the Y-axis direction vector of the metal ball verification point coordinate system; The third affine transformation matrix is obtained according to the X-axis direction vector, Y-axis direction vector, Z-axis direction vector of the metal ball verification point coordinate system, and the coordinates of the origin of the metal ball verification point coordinate system in the design engineering drawing image coordinate system.

4. The method according to claim 1, wherein The positioning system further includes a positioning unit, which is used to track the probe and the positioning member. The second affine transformation matrix from the reference array coordinate system to the probe verification point coordinate system is obtained, including: For each groove, obtaining a fifth affine transformation matrix from the positioning unit coordinate system corresponding to the groove to the probe coordinate system, and a sixth affine transformation matrix from the positioning unit coordinate system corresponding to the groove to the reference array coordinate system, wherein the positioning unit coordinate system is determined by the positioning unit, and the probe coordinate system is determined by the probe; For each groove, a seventh affine transformation matrix from the reference array coordinate system to the probe coordinate system corresponding to the groove is calculated based on the fifth affine transformation matrix and the sixth affine transformation matrix corresponding to the groove; Obtaining coordinates of each of the grooves in the reference array coordinate system according to a seventh affine transformation matrix corresponding to each of the grooves; The second affine transformation matrix is obtained according to the coordinates of each of the grooves in the reference array coordinate system.

5. The method according to claim 4, characterized in that For each groove, obtaining a fifth affine transformation matrix from the positioning unit coordinate system corresponding to the groove to the probe coordinate system, and a sixth affine transformation matrix from the positioning unit coordinate system corresponding to the groove to the reference array coordinate system, includes: In the preoperative stage, when the probe is placed in one of the grooves in turn, the positioning unit is used to track the probe and the positioning member to obtain the fifth affine transformation matrix and the sixth affine transformation matrix corresponding to the groove.

6. The method according to claim 5, characterized in that The relative position between the base plate and the reference array is adjustable, and the relative position between the base plate and the reference array is the same or different during the preoperative stage and when the CT image is obtained.

7. The method according to any one of claims 1 to 6, characterized in that The step of obtaining the coordinates of each reference metal ball in the metal ball verification point coordinate system according to the positions of each reference metal ball and each verification metal ball in the registration block in the obtained CT image comprises: Obtaining the coordinates of the center of each verification metal ball and the coordinates of the center of each reference metal ball in the CT image coordinate system; Obtaining an eighth affine transformation matrix from the CT image coordinate system to the metal verification point coordinate system according to the coordinates of the centers of the verification metal balls in the CT image coordinate system; The center coordinates of each reference metal ball in the metal verification point coordinate system are calculated based on the center coordinates of each reference metal ball in the CT image coordinate system and the eighth affine transformation matrix.

8. A device for obtaining a reference mark position, characterized in that: Applicable to a positioning system, the positioning system includes a registration block, the registration block includes a base plate and a reference array, the base plate includes a plurality of reference metal balls, the reference array includes a plurality of positioning members, a plurality of verification metal balls and a plurality of grooves for probes, the number of the positioning members, verification metal balls and grooves is greater than 2, and the device includes: a first matrix acquisition module, configured to obtain a first affine transformation matrix from a probe verification point coordinate system to a metal ball verification point coordinate system, wherein the probe verification point coordinate system is a three-dimensional coordinate system established based on the plurality of grooves, and the metal ball verification point coordinate system is a three-dimensional coordinate system established based on the plurality of verification metal balls; a second matrix obtaining module, configured to obtain a second affine transformation matrix from a reference array coordinate system to the probe verification point coordinate system, wherein the reference array coordinate system is a three-dimensional coordinate system established based on the plurality of positioning elements; a position obtaining module, configured to obtain the coordinates of each of the reference metal balls in the metal ball verification point coordinate system according to the positions of each of the reference metal balls and each of the verification metal balls in the registration block in the obtained CT image; The conversion module is used to obtain the coordinates of each of the reference metal balls in the reference array coordinate system according to the first affine transformation matrix, the second affine transformation matrix and the coordinates of each of the reference metal balls in the metal ball verification point coordinate system.

9. An electronic device, characterized in that: The method comprises a processor and a memory, wherein the memory stores machine executable instructions that can be executed by the processor, and the processor can execute the machine executable instructions to implement the method for obtaining the position of a reference mark point according to any one of claims 1 to 7.

10. A readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the method for obtaining the position of a reference mark point according to any one of claims 1 to 7 is implemented.

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