Medical navigation positioning system and automatic registration method

Abstract

The application discloses a medical navigation positioning system and an automatic registration method. An initial registration module determines a registration transformation matrix according to a physical space pose relationship between a tracking target and an optical tracker; a scanning device scans a surgical area to obtain actual orthotopic image data; the optical tracker identifies the positioners of the scanning device, a surgical tool and a reference frame to obtain first pose information, second pose information and third pose information during the scanning process; a first data processing module renders a virtual three-dimensional model of the surgical tool and a virtual three-dimensional anatomical model in a virtual space according to the above information and the registration transformation matrix, and simulates the scanning to generate virtual orthotopic image data according to imaging parameters; and a final state registration module updates the registration transformation matrix according to the error between the actual orthotopic image data and the virtual orthotopic image data, and adjusts the pose information of the above models based on the updated registration transformation matrix. The application realizes high-precision navigation registration correction in an automatic manner, and improves the positioning accuracy of the system.

Description

Technical Field

[0001] This application relates to the field of medical device technology, and in particular to a medical navigation and positioning system and an automatic registration method. Background Technology

[0002] In robot-assisted surgery, precise navigation and positioning are crucial for ensuring surgical safety and effectiveness. For example, in robot-assisted spinal surgery, navigation and positioning enable precise planning and real-time guidance of the surgical path, optimizing screw insertion angles and depths, reducing human error, and lowering the risk of neurovascular injury. However, because the spine is a non-rigid structure with micro-movements in the intervertebral spaces, and intraoperative manipulations (such as soft tissue traction and instrumentation) can easily exacerbate vertebral deformation, leading to relative displacement between the reference frame and the patient's spine. This risk of intraoperative displacement is particularly high in the more mobile cervical segments, and the further the operating distance from the reference frame, the more significant the error amplification effect.

[0003] Existing medical navigation and positioning systems mostly rely on preoperative CT (Computed Tomography) / MRI (Magnetic Resonance Imaging) images or intraoperative fluoroscopic images for initial registration in a single step. However, this static registration mode is difficult to respond to dynamic changes during surgery in real time (such as dynamic displacement of the patient's spinal tissue, loosening of the reference frame, and obstruction of optical tracking signals), which can easily lead to navigation deviations in the system. If these deviations cannot be corrected in time, they will significantly increase the risk of surgical complications for patients, severely limiting the clinical application effectiveness and safety of medical navigation and positioning systems. Summary of the Invention

[0004] Based on the above problems, this application provides a medical navigation and positioning system and an automatic registration method. The purpose is to solve the technical problem that the existing technology is unable to respond to dynamic changes during the operation in real time, which causes navigation deviations in the system, and to improve the positioning accuracy of the medical navigation and positioning system.

[0005] The embodiments of this application disclose the following technical solutions: In a first aspect, this application provides a medical navigation and positioning system, the system comprising: an initial registration module, a scanning device, an optical tracker, surgical tools, a first data processing module, a final registration module, and a reference frame; The initial registration module is used to determine a registration transformation matrix based on the physical spatial pose relationship between multiple tracking targets and the optical tracker; the registration transformation matrix is ​​used to characterize the spatial transformation relationship between the coordinate systems of the multiple tracking targets and the optical tracking coordinate system, and the multiple tracking targets include the scanning device, the surgical tools, and the anatomical structure of the surgical area; The scanning device is used to perform an orthogonal image scan of the surgical area at a target time to obtain actual orthogonal image data; the actual orthogonal image data is used to describe the two-dimensional imaging features of the surgical instruments and the anatomical structure of the surgical area. The optical tracker is used to identify an infrared locator on the scanning device to obtain first pose information during the orthogonal image scanning, and to identify an infrared locator on the surgical tool to obtain second pose information, and to identify an infrared locator on the reference frame to obtain third pose information. The first data processing module is used to render a preset three-dimensional model of a virtual surgical tool and a virtual three-dimensional anatomical model of the surgical area in the virtual space corresponding to the optical tracking coordinate system based on the first pose information, the second pose information, the third pose information and the registration transformation matrix, and to simulate the orthogonal image scanning in the virtual space based on the imaging parameters of the scanning device to generate virtual orthogonal image data. The final registration module is used to update the registration transformation matrix based on the error between the actual orthogonal image data and the virtual orthogonal image data, and to adjust the pose information of the virtual three-dimensional anatomical model and the virtual surgical tool based on the updated registration transformation matrix.

[0006] In an optional implementation, the reference frame is placed near the surgical area, and the infrared locator on the reference frame is a reflective patch array; the scanning device is further used to perform a three-dimensional image scan of the surgical area before performing the orthogonal image scan, so as to acquire three-dimensional anatomical structure image data of the surgical area; The optical tracker is also used for: During the three-dimensional image scanning process, the infrared locator on the scanning device is identified to obtain the first pose matrix, and the reflective array on the reference frame is identified to obtain the second pose matrix. Based on the first pose matrix and the second pose matrix, the first transformation matrix is ​​determined; the first transformation matrix is ​​used to characterize the spatial transformation relationship from the three-dimensional image coordinate system to the optical tracking coordinate system, the optical tracking coordinate system taking the position of the reflective array as the origin, and the three-dimensional image coordinate system taking the position of the infrared locator on the scanning device as the origin.

[0007] In an optional implementation, the system further includes a robotic arm equipped with an infrared locator and an actuator, the actuator being located at the end of the robotic arm and connected to the surgical tool; The optical tracker is also used for: During the movement of the robotic arm, an infrared positioner on the robotic arm is identified to obtain a third pose matrix; Based on the third pose matrix and the second pose matrix, a second transformation matrix is ​​determined; the second transformation matrix is ​​used to characterize the spatial transformation relationship from the robotic arm coordinate system to the optical tracking coordinate system, wherein the robotic arm coordinate system takes the position of the infrared positioner on the robotic arm as its origin.

[0008] In an optional implementation, the system further includes a data acquisition module for acquiring the rotation matrix and translation vector of the end effector relative to the robot arm coordinate system in multiple poses during the movement of the robot arm. The optical tracker is also used for: During the movement of the robotic arm, the infrared locator on the surgical tool is identified to obtain the pose of the tip of the surgical tool in the optical tracking coordinate system, thus obtaining a fourth pose matrix; The third transformation matrix is ​​determined using the tip calibration algorithm based on the fourth pose matrix, the rotation matrix, and the translation vector; the third transformation matrix is ​​used to characterize the spatial transformation relationship between the coordinate system of the tip of the surgical tool and the coordinate system of the robotic arm.

[0009] In an optional implementation, the initial registration module is specifically used for: The registration transformation matrix is ​​determined based on the first transformation matrix, the second transformation matrix, and the third transformation matrix.

[0010] In an optional implementation, the system further includes a second data processing module, which is specifically used for: Acquire the imaging parameters of the scanning device, the actual orthogonal image data, and the first pose information; Based on the imaging parameters of the scanning device, a perspective projection mapping relationship from the two-dimensional image plane to the three-dimensional image coordinate system is constructed; Based on the perspective projection mapping relationship, the first pose information and the actual orthogonal image data are mapped to three-dimensional space to construct a three-dimensional coordinate matrix; Based on the first transformation matrix, the three-dimensional coordinate matrix is ​​transformed into the optical tracking coordinate system to obtain the transformed coordinate matrix; Extract feature points of the surgical tool and / or feature points of the surgical area from the actual orthogonal image data; Based on the feature points of the surgical tool and the transformed coordinate matrix, determine the two-dimensional position information of the surgical tool; and / or based on the feature points of the anatomical structure and the transformed coordinate matrix, determine the two-dimensional position information of the anatomical structure.

[0011] In an optional implementation, the first data processing module is specifically used for: The imaging parameters of the scanning device, the three-dimensional anatomical structure image data, the first pose information, the second pose information, the third pose information, and the registration transformation matrix are obtained. Based on the third pose information and the registration transformation matrix, the three-dimensional anatomical structure image data is converted into the optical tracking coordinate system to generate a virtual three-dimensional anatomical model, and the virtual three-dimensional anatomical model is rendered in the virtual space. Based on the registration transformation matrix, the second pose information is transformed into the robotic arm coordinate system, and the transformed second pose information is transformed into the optical tracking coordinate system to obtain the target pose information; A preset 3D model of a virtual surgical tool is invoked, and the 3D model of the virtual surgical tool is rendered in the virtual space based on the target pose information; In the virtual space, a position corresponding to the first pose information is determined, and a virtual scanner is created at that position in combination with the imaging parameters; Using the virtual scanner, the orthogonal image scanning is simulated in the virtual space to generate the virtual orthogonal image data.

[0012] In an optional implementation, the first data processing module is further configured to: Feature points corresponding to the three-dimensional model of the virtual surgical tool are extracted from the virtual orthogonal image data to determine the two-dimensional position information of the three-dimensional model of the virtual surgical tool. And / or extract feature points corresponding to the virtual three-dimensional anatomical model from the virtual orthogonal image data to determine the two-dimensional position information of the virtual three-dimensional anatomical model.

[0013] In an optional implementation, the final state registration module includes: an error determination unit and a registration unit; The error determination unit is used for: The positional error of the surgical area is calculated based on the deviation distance between the two-dimensional positional information of the anatomical structure and the two-dimensional positional information of the virtual three-dimensional anatomical model. And / or the deviation distance between the two-dimensional position information of the surgical tool and the two-dimensional position information of the three-dimensional model of the virtual surgical tool is used to obtain the position error of the surgical tool; The error determination unit is further configured to determine the existence of a system registration error when the position error of the surgical area is greater than a first error value, and / or the position error of the surgical tool is greater than a second error value. The registration unit is used for: When the system registration error exists, the registration transformation matrix is ​​updated, and the pose information of the virtual three-dimensional anatomical model and the virtual surgical tool three-dimensional model is adjusted based on the updated registration transformation matrix.

[0014] In an optional implementation, the registration unit is specifically used for: Based on the three-dimensional coordinates of feature points in the rendered three-dimensional model of the virtual surgical tool and the two-dimensional position information of the surgical tool, the correction amount is determined; Alternatively, the correction amount can be determined based on the three-dimensional coordinates of feature points in the rendered virtual three-dimensional anatomical model and the two-dimensional position information of the anatomical structure. Alternatively, the correction amount can be determined based on the three-dimensional coordinates of feature points in the rendered virtual surgical tool 3D model and the three-dimensional coordinates of feature points in the rendered virtual 3D anatomical model, as well as the two-dimensional position information of the surgical tool and the two-dimensional position information of the anatomical structure. The registration unit is further used for: The registration transformation matrix is ​​updated based on the correction amount, and the pose information of the virtual three-dimensional anatomical model and the virtual surgical tool three-dimensional model is adjusted based on the updated registration transformation matrix.

[0015] In an optional implementation, the system further includes a timer for periodically outputting a positive-view film shooting prompt signal at preset fixed time intervals to prompt the operator to determine whether to perform the positive-view film shooting operation.

[0016] A second aspect of this application provides an automatic registration method for a navigation and positioning system, applied to a medical navigation and positioning system according to any one of the above-mentioned optional implementations, the method comprising: Based on the physical spatial pose relationship between multiple tracking targets and the optical tracker, a registration transformation matrix is ​​determined; the registration transformation matrix is ​​used to characterize the spatial transformation relationship between the coordinate systems of the multiple tracking targets and the optical tracking coordinate system, wherein the multiple tracking targets include the scanning device, the surgical instruments, and the anatomical structure of the surgical area; An anteroposterior image scan is performed on the surgical area at a target time to obtain actual anteroposterior image data; the actual anteroposterior image data is used to describe the two-dimensional imaging features of the surgical instruments and the anatomical structure of the surgical area. During the orthogonal image scan, an infrared locator on the scanning device is identified to obtain first pose information, and an infrared locator on the surgical tool is identified to obtain second pose information, and an infrared locator on the reference frame is identified to obtain third pose information. Based on the first pose information, the second pose information, the third pose information, and the registration transformation matrix, a preset three-dimensional model of a virtual surgical tool and a virtual three-dimensional anatomical model of the surgical area are rendered in the virtual space corresponding to the optical tracking coordinate system. The anteroposterior image scanning is simulated in the virtual space according to the imaging parameters of the scanning device to generate virtual anteroposterior image data. Based on the error between the actual anteroposterior image data and the virtual anteroposterior image data, the registration transformation matrix is ​​updated, and the pose information of the virtual three-dimensional anatomical model and the virtual surgical tool is adjusted based on the updated registration transformation matrix.

[0017] Compared with the prior art, this application has the following beneficial effects: In the technical solution of this application, firstly, the initial registration module of the medical navigation and positioning system can automatically determine a precise registration transformation matrix based on the physical spatial pose relationship between multiple tracking targets and the optical tracker. This registration transformation matrix can characterize the spatial transformation relationship between the coordinate systems of multiple tracking targets and the optical tracking coordinate system. The multiple tracking targets include the scanning device, surgical tools, and the anatomical structure of the surgical area, thereby reducing errors caused by manual operation and effectively reducing the navigation risk caused by initial registration deviation. Then, the scanning device can perform an orthogonal image scan of the surgical area at the target time to obtain actual orthogonal image data for describing the two-dimensional imaging features of the surgical tools and the anatomical structure of the surgical area, thereby providing the navigation system with a real and reliable intraoperative two-dimensional imaging benchmark and intuitively presenting the relative positional relationship between the surgical tools and the anatomical structure. Then, during orthogonal image scanning, the optical tracker can acquire first pose information by identifying infrared locators on the scanning device, second pose information by identifying infrared locators on the surgical instruments, and third pose information by identifying infrared locators on the reference frame. This ensures the spatiotemporal synchronization of the positioning data and improves the real-time performance and accuracy of pose acquisition. Then, the first data processing module can render a preset virtual 3D model of the surgical instruments and a virtual 3D anatomical model of the surgical area in the virtual space corresponding to the optical tracking coordinate system based on the first, second, and third pose information and the registration transformation matrix. This is done according to the imaging data from the scanning device. The parameters simulate anterior-view image scan in virtual space, generating virtual anterior-view image data that precisely corresponds to the actual anatomical structure of the surgical area. This achieves the fusion and visualization of virtual images and actual intraoperative images, enabling intuitive identification of anatomical structure deviations such as pedicle boundary misalignment. Finally, the final-state registration module updates the registration transformation matrix based on the error between the actual and virtual anterior-view image data, and adjusts the pose information of the virtual three-dimensional anatomical model and virtual surgical tools based on the updated registration transformation matrix. This solves the technical problem of navigation deviation caused by the inability of existing technologies to respond to dynamic changes during surgery in real time, significantly improving the positioning accuracy of the medical navigation and positioning system. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 This is a schematic diagram of the structure of a medical navigation and positioning system provided in an embodiment of this application; Figure 2 This is a schematic diagram of another medical navigation and positioning system provided in an embodiment of this application; Figure 3 A schematic diagram of the structure of another medical navigation and positioning system provided in the embodiments of this application; Figure 4 A flowchart of 2D-3D registration is provided for an embodiment of this application; Figure 5 This is a flowchart of an automatic registration method for a navigation and positioning system provided in an embodiment of this application. Detailed Implementation

[0020] As described earlier, current medical navigation and positioning systems mostly rely on preoperative CT (Computed Tomography) / MRI (Magnetic Resonance Imaging) images or intraoperative fluoroscopic images for initial registration in a single step. However, this static registration mode is difficult to respond to dynamic changes during surgery in real time (such as dynamic displacement of the patient's spinal tissue, loosening of the reference frame, and obstruction of optical tracking signals), which can easily lead to navigation deviations in the system. If these deviations cannot be corrected in time, they will significantly increase the risk of surgical complications for patients, severely limiting the clinical application effectiveness and safety of medical navigation and positioning systems.

[0021] The inventors discovered in their research that robotic-guided spinal surgery typically relies on a reference frame, intraoperative CT scan, robotic arms, and infrared tracking devices to align the patient's anatomical structures with the reference frame, thereby determining the true anatomical position of the spine. The robot then plans the pin path, and the robotic arm guides the insertion of the guidewire. However, during actual surgery, factors such as spinal tissue displacement, reference frame loosening, or obstruction of optical tracking signals can easily cause deviations in the spatial correspondence between preoperative or intraoperative images and the patient's actual anatomical structures, leading to inconsistencies between the displayed position of the virtual tool in the navigation system and its actual position. Simultaneously, while intraoperative X-ray fluoroscopy, a crucial basis for surgeons to determine pin placement, effectively reduces the risk of nerve damage, its two-dimensional projection information is difficult to match and verify with three-dimensional navigation data in real-time and automatically.

[0022] To overcome the shortcomings of existing technologies, the inventors discovered that by acquiring real-time intraoperative anteroposterior X-ray fluoroscopy images of the spine, the standard graduation marks on the front end of the robotic arm guide rod can be identified. Based on 2D-3D registration and comparison logic, the actual position of the guide rod graduation marks obtained during intraoperative fluoroscopy is matched and compared with the reference position of the graduation marks in the preoperative planned screw path. The 3D spatial error between the navigation result and the planned screw path pose is calculated, thereby achieving automatic detection and dynamic correction of navigation registration drift. Based on the above error correction results, the spatial pose of the virtual surgical tool in the navigation 3D image is simultaneously adjusted, which can accurately guide the actual surgical tool to complete operations such as pedicle screw incision, effectively improving the operational precision and clinical safety of spinal surgery. Specifically, a rigid guide rod with standard graduation marks is used as the fluoroscopic verification carrier. The length of the guide rod graduation marks is consistent with the direction and length of the preoperative planned screw path. Theoretically, the graduation mark pose under anteroposterior fluoroscopy should completely coincide with the planned pose; the deviation between the two reflects the offset between the navigation coordinate system and the actual coordinate system. Taking a plane perpendicular to the fluoroscopic direction as an example, the three-dimensional spinal image is projected onto this plane to obtain the vector information of the planned nail path. At the same time, the vector information of the guide rod tip under intraoperative fluoroscopy is obtained. By comparing the two, the translational deviation and rotational deviation are calculated and real-time registration correction is completed, which can effectively reduce the positioning error in the image space. This method is also applicable to the deviation correction of lateral phases and any plane.

[0023] Therefore, the inventors have proposed a medical navigation and positioning system and an automatic registration method. In this scheme, firstly, the initial registration module of the medical navigation and positioning system can automatically determine a precise registration transformation matrix based on the physical spatial pose relationship between multiple tracking targets and the optical tracker. This registration transformation matrix can characterize the spatial transformation relationship between the coordinate systems of multiple tracking targets and the optical tracking coordinate system. The multiple tracking targets include the scanning device, surgical tools, and the anatomical structure of the surgical area, thereby reducing errors caused by manual operation and effectively reducing the navigation risk caused by initial registration deviation. Then, the scanning device can perform an orthogonal image scan of the surgical area at the target time to obtain actual orthogonal image data for describing the two-dimensional imaging features of the surgical tools and the anatomical structure of the surgical area, thereby providing the navigation system with a real and reliable intraoperative two-dimensional imaging benchmark and intuitively presenting the relative positional relationship between the surgical tools and the anatomical structure. Then, during orthogonal image scanning, the optical tracker can acquire first pose information by identifying infrared locators on the scanning device, second pose information by identifying infrared locators on the surgical instruments, and third pose information by identifying infrared locators on the reference frame. This ensures the spatiotemporal synchronization of the positioning data and improves the real-time performance and accuracy of pose acquisition. Then, the first data processing module can render a preset virtual 3D model of the surgical instruments and a virtual 3D anatomical model of the surgical area in the virtual space corresponding to the optical tracking coordinate system based on the first, second, and third pose information and the registration transformation matrix. This is done according to the imaging data from the scanning device. The parameters simulate anterior-view image scan in virtual space, generating virtual anterior-view image data that precisely corresponds to the actual anatomical structure of the surgical area. This achieves the fusion and visualization of virtual images and actual intraoperative images, enabling intuitive identification of anatomical structure deviations such as pedicle boundary misalignment. Finally, the final-state registration module updates the registration transformation matrix based on the error between the actual and virtual anterior-view image data, and adjusts the pose information of the virtual three-dimensional anatomical model and virtual surgical tools based on the updated registration transformation matrix. This solves the technical problem of navigation deviation caused by the inability of existing technologies to respond to dynamic changes during surgery in real time, significantly improving the positioning accuracy of the medical navigation and positioning system.

[0024] To enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present application, and not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present application.

[0025] System Implementation Examples

[0026] This application provides a medical navigation and positioning system, wherein... Figure 1 This is a schematic diagram of the structure of a medical navigation and positioning system provided in an embodiment of this application, as shown below. Figure 1 As shown, the medical navigation and positioning system includes: an initial registration module 101, a scanning device 102, an optical tracker 103 (i.e., NDI, short for Northern Digital Inc.), surgical instruments 104, a first data processing module 105, a final registration module 106, and a reference frame 107. The reference frame 107 is placed near the patient's surgical area (such as the patient's spinal region) and is equipped with an infrared locator 1071 (such as a reflective patch array or a reflective ball array). Figure 1 You can see the connections between several modules.

[0027] The initial registration module 101 is used to perform three-dimensional initial registration of the medical navigation and positioning system. It can determine the registration transformation matrix based on the physical spatial pose relationship between multiple tracking targets and the optical tracker. The registration transformation matrix is ​​used to characterize the spatial transformation relationship between the coordinate systems of multiple tracking targets and the optical tracking coordinate system. The multiple tracking targets include the scanning device, surgical tools, and the anatomical structure of the surgical area. The scanning device 102 is used to capture two-dimensional image images (such as two-dimensional image images during surgery, i.e., actual anteroposterior image data) and three-dimensional image images of the patient's surgical area. It can perform anteroposterior image scanning of the surgical area at the target time to obtain actual anteroposterior image data. The actual anteroposterior image data is used to describe the two-dimensional imaging characteristics of the anatomical structure of the surgical tools and the surgical area. The optical tracker 103 is used to track and position the scanning device 102, the surgical tools 104, and the surgical area. When performing anteroposterior image scanning, it can identify the infrared locator on the scanning device to obtain first pose information, identify the infrared locator on the surgical tool to obtain second pose information, and identify the infrared locator on the reference frame to obtain third pose information.

[0028] The first data processing module 105 is used to simulate an orthogonal image scan in virtual space to generate virtual orthogonal image data of the patient's surgical area. Based on the first pose information, second pose information, third pose information, and registration transformation matrix, it renders a preset virtual three-dimensional model of the virtual surgical tool and a virtual three-dimensional anatomical model of the surgical area in the virtual space corresponding to the optical tracking coordinate system. It also simulates an orthogonal image scan in virtual space based on the imaging parameters of the scanning device to generate virtual orthogonal image data. The final registration module 106 includes an error determination unit 1061 and a registration unit 1062, specifically used to perform final registration of the medical navigation and positioning system based on the error between the actual orthogonal image data and the virtual orthogonal image data. For ease of description, the medical navigation and positioning system will be referred to as the system below.

[0029] In addition to the modules mentioned above, the medical navigation and positioning system also includes Figure 2 The diagram shows a robotic arm 108, a data acquisition module 109, and a second data processing module 110. The robotic arm 108 is equipped with an infrared locator 1081 and an actuator 1082. The actuator 1082 is located at the end of the robotic arm 1081 and connected to the surgical instrument 104. The data acquisition module 109 is used to acquire the rotation matrix and translation vector of the actuator 1082 relative to the robotic arm coordinate system in multiple poses of the robotic arm 108 during its movement. The second data processing module 110 is used to extract the two-dimensional position information of the surgical instrument and / or the two-dimensional position information of the anatomical structures of the surgical area from the actual anteroposterior image data captured during surgery.

[0030] It should be noted that before the medical navigation and positioning system is operational, the patient's position must be properly set up, the drapes disinfected, and the reference frame 107 placed near the patient's surgical area (e.g., ...). Figure 3 Preoperative preparations include the area of ​​the spinous process within approximately 15 cm of the patient's spine shown in the image.

[0031] After completing preoperative preparations, the medical navigation and positioning system can be activated, and the system can then automatically perform initial registration. Specifically, the system can first perform a three-dimensional image scan of the surgical area using the scanning device 102 to acquire three-dimensional anatomical structure image data of the surgical area. This three-dimensional anatomical structure image data can be CT (Computed Tomography) image data, including the anatomical structure of the surgical area. Subsequently, during the three-dimensional image scan, the system can identify the infrared locator 1021 on the scanning device 102 through the optical tracker 103. By tracking the position and attitude of the infrared locator 1021, the first pose matrix is ​​calculated, which reflects the spatial pose state of the scanning device 102 relative to the optical tracking coordinate system E0. At the same time, the optical tracker 103 can identify the reflective array 1071 on the reference frame 107. By tracking the positioning of the reflective array 1071, the second pose matrix is ​​calculated, which reflects the overall spatial pose relationship of the reference frame 107 relative to the optical tracking coordinate system E0. Then, the optical tracker 103 can reverse the coordinates of the optical tracking coordinate system E0 to the coordinate system of the reference frame itself based on the first pose matrix, and forward the coordinates of the three-dimensional image coordinate system E1 to the optical tracking coordinate system E0 based on the second pose matrix. Then, the transformation results of the two are multiplied to obtain the first transformation matrix E1→E0, which is used to characterize the spatial transformation relationship from the three-dimensional image coordinate system E1 to the optical tracking coordinate system E0. This can quickly obtain an accurate registration transformation matrix, reduce errors caused by manual operation, and effectively reduce the navigation risk caused by the initial registration deviation.

[0032] It should be noted that the optical tracking coordinate system mentioned above takes the position of the reflective patch array as its origin, while the three-dimensional image coordinate system takes the position of the infrared locator on the scanning device as its origin.

[0033] After obtaining the first transformation matrix E1→E0, the system also needs to register the robotic arm and calibrate the surgical tools. Specifically, the system can first identify the infrared positioner 1081 on the robotic arm 108 during its movement using the optical tracker 103. By tracking the position and attitude of the infrared positioner 1081, the system calculates the third pose matrix, which can be used to characterize the pose relationship of the infrared positioner 1081 on the robotic arm 108 relative to the optical tracking coordinate system E0. Then, the optical tracker 103 can perform an inverse transformation on the second pose matrix to obtain the transformation relationship from the optical tracking coordinate system to E0 to the reference frame's own coordinate system. Finally, the third pose matrix is ​​multiplied by the inversely transformed second pose matrix to obtain the second transformation matrix E2→E0, which characterizes the rigid spatial transformation relationship from the robotic arm coordinate system E2 to the optical tracking coordinate system E0. Among them, the robotic arm coordinate system E2 takes the position of the infrared positioner 1081 on the robotic arm as the origin. Through this transformation matrix, the unified transformation of any point and pose in the robotic arm coordinate system to the optical tracking coordinate system can be realized, providing a coordinate transformation basis for subsequent multi-coordinate system linkage registration and surgical navigation positioning.

[0034] Subsequently, the system can identify the infrared locator 1041 on the surgical tool 104 during the movement of the robotic arm using the optical tracker 103, to obtain the pose of the tip of the surgical tool in the optical tracking coordinate system E0, thus obtaining a fourth pose matrix. Then, the optical tracker 103 can use a tip calibration algorithm based on the aforementioned fourth pose matrix and the rotation matrix and translation vector of the end effector 1082 relative to the robotic arm coordinate system in multiple poses of the robotic arm 108 during the movement process, acquired by the data acquisition module 109, to determine a third transformation matrix E3→E2, which characterizes the spatial transformation relationship between the coordinate system E3 where the tip of the surgical tool is located and the robotic arm coordinate system E2. The calibration process requires the tip of the surgical tool to be fixed at a point, and the robotic arm movement causes this point to rotate or swing, acquiring information from multiple frames (to prevent errors from occurring in a single frame) to determine the pose information of the tip in the robotic arm coordinate system, and then associating it with the robotic arm coordinate system. Specifically, the tip calibration algorithm is used to accurately calibrate the position and orientation of the surgical tool tip relative to the end effector coordinate system of the robotic arm by minimizing the objective function, thereby obtaining the surgical tool calibration matrix (i.e., the third transformation matrix E3→E2). The objective function is as follows:

[0035] Where P represents the fixed 3D coordinates (i.e., the quantity to be determined) of the tip of the surgical instrument in the robotic arm coordinate system (i.e., E3); Q i R represents the three-dimensional coordinates of the tip of the surgical instrument in the navigation coordinate system (E0) as measured by the optical tracker 103 in the i-th frame; i This represents the 3×3 orthogonal rotation matrix of the end effector 1082 of the robotic arm 108 relative to the robotic arm coordinate system (E3) in the i-th frame; t i R represents the 3×1 translation vector of the end effector 1082 of the robotic arm 108 relative to the robotic arm coordinate system in the i-th frame; i P+t i This represents the coordinates of the surgical tool's tip P after transforming it from the robotic arm coordinate system to the current end effector coordinate system and then back to the robotic arm coordinate system. This is equivalent to describing the real-time position of the surgical tool's tip in the robotic arm coordinate system as it moves with the robotic arm; ||² represents the square of the Euclidean distance (i.e., the squared L2 norm), used to quantify R. i P+t i With Q i The coordinate error between them; min represents the P value that minimizes the sum of squared errors for all measurement frames i.

[0036] It should be noted that the objective function describes the synchronous movement of the tip P of the surgical tool 104, rigidly mounted on its end effector 1082, with the end effector 1082 when the robotic arm 108 is in different poses. Its position in the robotic arm coordinate system can be determined by R. i P+t i Precise description; simultaneously, the system will track the position Q of the tip P of the surgical tool 104 in the tracking coordinate system E0 in real time. i By minimizing R in all measurement frames i P+t i With Q i By using the sum of squared Euclidean distances, the fixed coordinates P of the tool tip in the robotic arm coordinate system can be accurately calculated, thus completing the calibration of the surgical tool tip.

[0037] Subsequently, the system can construct a registration transformation matrix containing information from the first transformation matrix, the second transformation matrix, and the third transformation matrix based on the first transformation matrix, the second transformation matrix, and the third transformation matrix through the initial registration module 101. This information can accurately reflect the spatial transformation relationship between the coordinate systems of multiple tracking targets (i.e., the anatomical structures of the scanning device, surgical tools, and surgical area) and the optical tracking coordinate system.

[0038] After the system completes initial registration, it can enter the normal operation phase. When medical staff activate the system's anteroposterior image scanning function at the critical moment of the surgery (i.e., the target moment), the system can first use the scanning device 102 to perform an anteroposterior image scan of the patient's surgical area at that critical moment to obtain actual anteroposterior image data (i.e., Figure 4 As shown in the ImgrealAP, the actual anteroposterior image data can describe the two-dimensional imaging features of the surgical instrument 104 and the anatomical structure of the surgical area, thereby providing a real and reliable intraoperative two-dimensional imaging benchmark for the navigation system and intuitively presenting the relative positional relationship between the surgical instrument and the anatomical structure. Subsequently, the system can identify the infrared locator 1021 on the scanning device 102 when performing the above-mentioned anteroposterior image scanning through the optical tracker 103. By tracking the position and attitude of the infrared locator 1021, the first pose information (i.e., position and attitude) is calculated. This information is used to characterize the infrared locator 1021 on the scanning device 102. The optical tracker 103 can identify the infrared locator 1041 on the surgical tool 104 and calculate the second pose information by tracking the position of the infrared locator 1041 relative to the optical tracker coordinate system. This information is used to characterize the pose relationship of the infrared locator 1041 on the surgical tool 104 relative to the optical tracker coordinate system. The optical tracker 103 can also identify the infrared locator (such as a reflective array sticker) 1071 on the reference frame 107 and calculate the third pose information by tracking the position of the infrared locator 1071. This ensures the spatiotemporal synchronization of the positioning data and improves the real-time performance and accuracy of the pose acquisition.

[0039] It should be noted that during the surgery, surgical instruments will fall into the surgical area. Therefore, by performing an anteroposterior imaging scan of the surgical area, an image containing two-dimensional image information of the surgical instruments and anatomical structures can be obtained (i.e., actual anteroposterior imaging data).

[0040] After completing the anteroposterior image scanning and pose information acquisition, the system can use the first data processing module 105 to render a preset virtual surgical tool 3D model and a virtual 3D anatomical model of the surgical area in the virtual space corresponding to the optical tracking coordinate system E0, based on the first pose information, second pose information, third pose information, and registration transformation matrix. Then, according to the imaging parameters of the scanning device 102, the system simulates the aforementioned anteroposterior image scanning in this virtual space to generate virtual anteroposterior image data (i.e., Figure 4 The ImgvirtualAP in the system enables the fusion and visualization of virtual images with actual intraoperative images, thereby allowing for the intuitive identification of anatomical structural deviations such as pedicle boundary misalignment.

[0041] Specifically, the system can first retrieve the imaging parameters and three-dimensional anatomical structure image data of the scanning device through the first data processing module 105, as well as the previously acquired first pose information, second pose information, third pose information, and registration transformation matrix; then, based on the third pose information and registration transformation matrix, the first data processing module 105 can use the E1→E0 transformation relationship to transform the three-dimensional anatomical structure image data into the optical tracking coordinate system E0, generate a virtual three-dimensional anatomical model of the patient's surgical area, and render the virtual three-dimensional anatomical model in virtual space; then, based on the registration transformation matrix, the first data processing module 105 can use the E3→E2 transformation relationship to transform the second pose information into the robotic arm coordinate system E2, and use the E2→E0 transformation relationship... The converted second pose information is transferred to the optical tracking coordinate system E0 to obtain the target pose information. Then, the first data processing module 105 can call the preset virtual surgical tool 3D model and render the virtual surgical tool 3D model in the virtual space based on the above target pose information. Then, the first data processing module 105 can determine the position corresponding to the first pose information in the virtual space and create a virtual scanner at that position in combination with the imaging parameters of the scanning device 102. Finally, the first data processing module 105 can use the virtual scanner to simulate an orthogonal image scan in the virtual space, and finally generate virtual orthogonal image data that matches the actual scanning scene, providing standard reference data for subsequent virtual-real image comparison, registration error calculation and navigation deviation correction.

[0042] It should be noted that, because the above process uses the same imaging parameters and first pose information as the actual scanner, a corresponding virtual vertebral body can be simulated in virtual space. The plane containing this virtual vertebral body is the same plane containing the virtual anteroposterior image. By projecting the virtual 3D image (including the 3D model of the virtual surgical tool and the virtual 3D anatomical model) onto this plane, the virtual anteroposterior image is obtained. The virtual anteroposterior image contains the 2D image information of the 3D model of the virtual surgical tool and the virtual 3D anatomical model.

[0043] After obtaining actual and virtual orthogonal image data, the system can acquire the imaging parameters of the scanning device (such as focal length, imaging angle, etc.), the actual orthogonal image data acquired during the operation, and the aforementioned first pose information through the second data processing module 110. Then, based on the imaging parameters of the scanning device, the second data processing module 110 can construct a perspective projection mapping relationship from the two-dimensional image plane to the three-dimensional image coordinate system, realize the precise association between the two-dimensional image and the three-dimensional space, and based on the perspective projection mapping relationship, map the aforementioned first pose information and actual orthogonal image data into the three-dimensional space to construct a three-dimensional coordinate matrix. In this case, due to the use of perspective projection, the planar orthogonal image is transformed into a cone in space. This cone corresponds to the three-dimensional coordinate matrix, and the bottom surface of the cone is the plane where the orthogonal image is located. Then, the second data processing module 110 can transform the three-dimensional coordinate matrix to the optical tracking coordinate system E0 based on the first transformation matrix (i.e., E1→E0) to obtain the transformed coordinate matrix. That is, the cone-shaped body is placed in the optical tracking coordinate system for position representation. Thus, after extracting the feature points of the anatomical structure or the feature points of the surgical tool from the actual anteroposterior image, its two-dimensional position information can be determined in the two-dimensional space of the bottom surface of the cone-shaped body (i.e., the two-dimensional position information is reflected by the two-dimensional coordinates of their respective feature points, which are generally points on the key contour boundary. For example, for surgical tools, the tip can be selected as the feature point). The anatomical outline of the patient's surgical area may require multiple feature points for characterization. Then, the second data processing module 110 can extract feature points of the surgical tool 104 and / or feature points of the surgical area from the above-mentioned actual anteroposterior image data. Finally, the second data processing module 110 can determine the two-dimensional position information of the surgical tool 104 based on the feature points of the surgical tool and the transformed coordinate matrix; and / or determine the two-dimensional position information of the anatomical structure based on the feature points of the anatomical structure and the transformed coordinate matrix, providing accurate tool position data support for subsequent comparison and registration error calculation between the two-dimensional actual image and the three-dimensional virtual image.

[0044] At the same time, the system can use the first data processing module 105 to extract feature points corresponding to the three-dimensional model of the virtual surgical tool from the virtual orthogonal image data to determine the two-dimensional position information of the three-dimensional model of the virtual surgical tool; and / or extract feature points corresponding to the virtual three-dimensional anatomical model from the virtual orthogonal image data to determine the two-dimensional position information of the virtual three-dimensional anatomical model, providing accurate tool position data support for subsequent comparison of two-dimensional actual images and three-dimensional virtual images and calculation of registration errors.

[0045] It should be noted that since the spatial position of the virtual space is described using an optical tracking coordinate system, once the feature points are obtained on the virtual orthographic image, their two-dimensional position information can be directly obtained on the virtual plane on which the virtual orthographic image is located.

[0046] After obtaining the two-dimensional position information of the surgical tool 104 on the two-dimensional image plane, the two-dimensional position information of the anatomical structure of the surgical area, the two-dimensional position information of the virtual surgical tool on the two-dimensional image plane, and the two-dimensional position information of the virtual three-dimensional anatomical model on the two-dimensional image plane, the system can use the final state registration module 106 to update the registration transformation matrix based on the above two-dimensional position information, and accurately adjust the pose information of the virtual three-dimensional anatomical model and the virtual surgical tool three-dimensional model based on the updated registration transformation matrix. This solves the technical problem of navigation deviation caused by the difficulty of responding to dynamic changes during the operation in real time in the existing technology, and greatly improves the positioning accuracy of the medical navigation and positioning system.

[0047] Specifically, the final state registration module 106 can utilize Figure 5 The error determination unit 1061 shown uses the two-dimensional projection point set mean square error formula to calculate the position error of the surgical area based on the deviation distance between the two-dimensional position information of the anatomical structure and the two-dimensional position information of the virtual three-dimensional anatomical model. The two-dimensional projection point set mean square error formula can be shown as formula (1). This formula can be used to quantify the overall position deviation of the same source feature points in the actual orthogonal image and the virtual orthogonal image. It is the core evaluation index for judging the image registration accuracy. The smaller the calculated error value, the higher the matching overlap between the actual image and the virtual image, and the higher the overall coordinate registration accuracy of the system.

[0048] (1)

[0049] Among them, Error 2D The mean square error of the two-dimensional projection point set (i.e., the positional error of the surgical area) can intuitively reflect the overall deviation between the feature points of the real image and the virtual image; N is the total number of all extracted matching feature points, including corresponding feature points such as pedicles, spinous processes, and surgical tool outlines; i represents the i-th set of matching feature points; f i real f represents the two-dimensional coordinates of the i-th feature point within the actual orthogonal image data; i virtual Let be the two-dimensional coordinates of the i-th feature point within the virtual orthogonal image data; The value represents the two-dimensional Euclidean distance, used to characterize the positional difference between two sets of coordinates. The formula as a whole calculates the average of the squared distances of all feature points to obtain the overall registration mean square error.

[0050] Optionally, the error determination unit 1061 may also use the following formula (2) to obtain the position error of the surgical tool based on the deviation distance between the two-dimensional position information of the surgical tool and the two-dimensional position information of the three-dimensional model of the virtual surgical tool. The specific formula is shown in formula (2): (2) in, This indicates the positional error of the surgical instruments; Two-dimensional positional information of surgical instruments can be represented, for example, by the coordinates of the tip of the surgical instrument; The two-dimensional position information of the virtual surgical tool can be represented, for example, by the coordinates of the tip of the virtual surgical tool. Then, the error determination unit 1061 can determine whether to update the registration transformation matrix through a comprehensive error decision method. That is, when the position error of the surgical area is greater than a first error value (e.g., 1.5 mm), and / or the position error of the surgical tool is greater than a second error value (e.g., 1.0 mm), it can be determined that there is a system registration error. The comprehensive error decision method is as follows:

[0051] Here, Trigger Correction represents a Boolean flag, where true indicates that correction is triggered (i.e., 2D-3D registration), and false indicates that no correction is needed; Error 2D Indicates two-dimensional registration error; This indicates the positional error of the surgical instruments.

[0052] Finally, the final registration module 106 can use the registration unit 1062 to update the registration transformation matrix when there is a system registration error, and adjust the pose information of the virtual three-dimensional anatomical model and the virtual surgical tool three-dimensional model based on the updated registration transformation matrix. Specifically, if the two-dimensional registration error is greater than the first error value (e.g., 1.5 mm) and the position error of the surgical tool is greater than the second error value (e.g., 1.0 mm), the registration unit 1062 can determine that there is a positional deviation between the surgical tool and the virtual surgical tool (i.e., there is a system registration error), and calculate the correction amount ΔT based on the three-dimensional coordinates of each feature point in the rendered virtual three-dimensional anatomical model, the three-dimensional coordinates of each feature point in the rendered virtual surgical tool three-dimensional model, and the first feature data using the correction amount calculation formula shown in formula (3); specifically, the registration unit 1062 can determine the correction amount ΔT based on the three-dimensional coordinates of the feature points in the rendered virtual surgical tool three-dimensional model and the two-dimensional position information of the surgical tool; or, based on the three-dimensional coordinates of the feature points in the rendered virtual three-dimensional anatomical model and the two-dimensional position information of the anatomical structure; or, based on the three-dimensional coordinates of the feature points in the rendered virtual surgical tool three-dimensional model and the three-dimensional coordinates of the feature points in the rendered virtual three-dimensional anatomical model, as well as the two-dimensional position information of the surgical tool and the two-dimensional position information of the anatomical structure; wherein, the specific correction amount calculation formula is as follows: (3) Wherein, ΔT is the three-dimensional registration correction quantity to be solved, which is a rigid transformation matrix that has both rotation and translation parameters. Its function is to compensate for and correct the registration deviation that currently exists in the system. This represents a process of iterating through the problem and selecting the optimal ΔT that minimizes the subsequent error function values. ∏( X is a perspective projection operator that can map and transform three-dimensional spatial coordinate points to a two-dimensional imaging plane. As mentioned before, it projects a virtual three-dimensional model onto the virtual plane containing the virtual orthographic image, and then transforms it to obtain two-dimensional information. i X represents the coordinates of the i-th virtual 3D feature point, taken from the 3D point data of the preoperatively reconstructed human anatomical model or surgical tool model. i real The coordinates of the i-th real two-dimensional feature point are the corresponding feature points extracted from the actual anteroposterior images acquired during the operation. It represents the squared two-dimensional Euclidean distance, used to quantify the positional deviation between coordinates.

[0053] Then, the registration unit 1062 can update the registration transformation matrix T based on the correction amount ΔT. current T currentnew Among them, such as Figure 4 As shown, T currentnew =T current ·ΔT. Then the registration unit 1064 can be based on the updated registration transformation matrix T. currentnew Adjust the pose information of the virtual 3D anatomical model and the virtual surgical tool 3D model.

[0054] Optionally, if the two-dimensional registration error is less than or equal to the first error value, and / or the surgical tool position error is less than or equal to the second error value, then it is determined that there is no positional deviation between the surgical tool and the virtual surgical tool, and updating the registration transformation matrix is ​​prohibited.

[0055] In one feasible implementation, the system may further include a timer that can be used to periodically output a positive view film shooting prompt signal at preset fixed time intervals (e.g., 10 minutes) to prompt the operator to determine whether to perform the positive view film shooting operation.

[0056] It should be noted that since errors accumulate during surgery, the timing starts when the reference frame is installed. A timer is set to prompt the doctor to take an anteroposterior radiograph at regular intervals to determine if any deviation has occurred, which effectively improves the positioning accuracy of the system.

[0057] Optionally, the system can also identify specific surgical instruments used by the operator that are prone to causing significant displacement (such as drills, ultrasonic bone scalpels, etc., surgical tools that grind or cut bone or alter interpyramidal structures). These instruments can be pre-modeled in the system and equipped with infrared locators, or they can be identified using optical trackers. The system can then determine the start time of the operation (either by recognizing the instrument entering the target operating area through image recognition or by the operator providing an interactive prompt to begin instrument operation). This time point can be preset as the starting point for timing. For example, a prompt can be set to appear after 10 minutes, or a signal can be output to indicate when the instrument exits the operation (either by recognizing the instrument exiting the operation screen through image recognition or by the doctor providing an interactive prompt to end the operation), prompting the operator to determine whether to perform an anteroposterior radiograph.

[0058] In another feasible implementation, after completing the above registration operation, the system can perform a cyclic fluoroscopic verification operation. This operation is a dynamic accuracy assurance link in the surgical navigation process, and the system can ensure stable intraoperative navigation accuracy through continuous verification. Specifically, after completing a stage of the open-path operation (i.e., invasive or non-invasive operations performed on the patient's surgical area based on the preoperatively planned path during surgical navigation), or during the operation when the operator determines that accuracy verification is necessary, the above-mentioned anteroposterior image scan can be triggered again to re-acquire the actual anteroposterior image data of the surgical area. Subsequently, the extraction of actual image features, calculation of registration error, and correction of the registration matrix are repeated. Through this cyclic verification method, navigation deviations are corrected in real time, ensuring the consistency between the virtual scene and the actual surgical scene throughout the entire operation. This avoids the decrease in navigation accuracy caused by factors such as intraoperative positional deviation and equipment errors, providing continuous accuracy assurance for surgical safety.

[0059] After completing the cyclic fluoroscopic verification, the system can perform a final confirmation of the navigation accuracy throughout the entire surgical procedure. Specifically, after all the preset surgical paths have been executed, the system first acquires the final actual anteroposterior image of the surgical area, then acquires the actual anteroposterior image and extracts feature coordinates, constructs a virtual scene and completes coordinate transformation, matches feature points and calculates registration errors, corrects the registration matrix, and comprehensively reviews and evaluates the registration accuracy and error control effects throughout the entire surgical procedure. Once it is confirmed that all operations meet the preset standards and the navigation accuracy meets the surgical requirements, the entire surgical navigation process is officially completed, ensuring the safety and precision of the surgical operation and providing reliable technical reference for surgical completion and subsequent recovery.

[0060] The medical navigation and positioning system provided in this application automatically transforms the three-dimensional anatomical structure image data of the patient's surgical area from the three-dimensional image coordinate system to the optical tracking coordinate system. This enables the rapid and accurate registration transformation matrix, reducing errors caused by manual operation and effectively mitigating navigation risks due to initial registration deviations. It also achieves visualization by fusing virtual images with actual intraoperative images, allowing for intuitive identification of anatomical structure offsets such as pedicle boundary misalignment. Finally, the final-state registration module updates the registration transformation matrix based on the error between the actual and virtual anteroposterior image data, and adjusts the pose information of the virtual three-dimensional anatomical model and virtual surgical tools based on the updated matrix. This solves the technical problem of navigation deviations caused by the inability to respond to dynamic changes during surgery in real time, significantly improving the positioning accuracy of the medical navigation and positioning system.

[0061] Method Implementation Examples

[0062] This application provides an embodiment of an automatic registration method for a navigation and positioning system, which is applied to the medical navigation and positioning system described in the above system embodiment. It should be noted that the steps shown in the flowcharts of the accompanying drawings can be executed in a computer system such as a set of computer-executable instructions, and although a logical order is shown in the flowcharts, in some cases, the steps shown or described may be performed in a different order than that shown here.

[0063] See Figure 5 The figure is a flowchart of an automatic registration method for a navigation and positioning system provided in an embodiment of this application. Figure 5 As shown, the method includes the following steps: Step S501: Determine the registration transformation matrix based on the physical spatial pose relationship between multiple tracking targets and optical trackers.

[0064] In step S501, the registration transformation matrix is ​​used to characterize the spatial transformation relationship between the coordinate systems of multiple tracking targets and the optical tracking coordinate system. The multiple tracking targets include scanning equipment, surgical tools, and the anatomical structure of the surgical area.

[0065] Optionally, the first transformation matrix can be obtained through the following process: performing a three-dimensional image scan of the surgical area to acquire three-dimensional anatomical structure image data of the surgical area; during the three-dimensional image scan, identifying the infrared locator on the scanning device to obtain the first pose matrix, and identifying the reflective array on the reference frame to obtain the second pose matrix; based on the first pose matrix and the second pose matrix, determining the first transformation matrix, which is used to characterize the spatial transformation relationship from the three-dimensional image coordinate system to the optical tracking coordinate system, with the position of the reflective array as the origin of the optical tracking coordinate system and the position of the infrared locator on the scanning device as the origin of the three-dimensional image coordinate system.

[0066] Optionally, during the movement of the robotic arm, the system can identify the infrared positioner on the robotic arm to obtain a third pose matrix; based on the third pose matrix and the second pose matrix, a second transformation matrix is ​​determined; the second transformation matrix is ​​used to characterize the spatial transformation relationship from the robotic arm coordinate system to the optical tracking coordinate system, with the position of the infrared positioner on the robotic arm as the origin.

[0067] Optionally, during the movement of the robotic arm, the system can acquire the rotation matrix and translation vector of the end effector relative to the robotic arm coordinate system in multiple poses; during the movement of the robotic arm, the system can identify the infrared positioner on the surgical tool to obtain the pose of the tip of the surgical tool in the optical tracking coordinate system, thus obtaining the fourth pose matrix; and use the tip calibration algorithm to determine the third transformation matrix based on the fourth pose matrix, rotation matrix, and translation vector; the third transformation matrix is ​​used to characterize the spatial transformation relationship from the coordinate system of the surgical tool tip to the coordinate system of the robotic arm.

[0068] Optionally, the system can determine the registration transformation matrix based on the first transformation matrix, the second transformation matrix, and the third transformation matrix.

[0069] Step S502: Perform an orthogonal image scan on the surgical area at the target time to obtain actual orthogonal image data.

[0070] In step S502, the actual anteroposterior image data is used to describe the two-dimensional imaging features of the anatomical structures of the surgical instruments and surgical area.

[0071] Optionally, after obtaining the actual anteroposterior image data, the system can acquire the imaging parameters of the scanning device, the actual anteroposterior image data, and the first pose information; then, based on the imaging parameters of the scanning device, perform digital image reconstruction on the actual anteroposterior image, i.e., construct a perspective projection mapping relationship from a two-dimensional image plane to a three-dimensional image coordinate system; then, based on the perspective projection mapping relationship, map the first pose information and the actual anteroposterior image data into three-dimensional space to construct a three-dimensional coordinate matrix; then, based on a first transformation matrix, transform the three-dimensional coordinate matrix to the optical tracking coordinate system to obtain the transformed coordinate matrix; then, extract the feature points of the surgical tool and / or the feature points of the surgical area from the actual anteroposterior image data; finally, based on the feature points of the surgical tool and the transformed coordinate matrix, determine the two-dimensional position information of the surgical tool; and / or based on the feature points of the anatomical structure and the transformed coordinate matrix, determine the two-dimensional position information of the anatomical structure.

[0072] In step S503, during the anteroposterior image scanning, an infrared locator on the scanning device is identified to obtain first pose information, and an infrared locator on the surgical instrument is identified to obtain second pose information, and an infrared locator on the reference frame is identified to obtain third pose information.

[0073] Optionally, the reference frame is placed near the surgical area, and the infrared locators on the reference frame are a reflective patch array.

[0074] Step S504: Based on the first pose information, the second pose information, the third pose information and the registration transformation matrix, render the preset virtual surgical tool 3D model and the virtual 3D anatomical model of the surgical area in the virtual space corresponding to the optical tracking coordinate system, and simulate the anteroposterior image scanning in the virtual space according to the imaging parameters of the scanning device to generate virtual anteroposterior image data.

[0075] Optionally, virtual anteroposterior image data can be generated through the following process: First, acquire the imaging parameters of the scanning device, three-dimensional anatomical structure image data, first pose information, second pose information, third pose information, and registration transformation matrix; then, based on the third pose information and registration transformation matrix, convert the three-dimensional anatomical structure image data into the optical tracking coordinate system to generate a virtual three-dimensional anatomical model, and render the virtual three-dimensional anatomical model in virtual space; then, based on the registration transformation matrix, convert the second pose information into the robotic arm coordinate system, and convert the converted second pose information into the optical tracking coordinate system to obtain the target pose information; then, call the preset virtual surgical tool three-dimensional model, and render the virtual surgical tool three-dimensional model in virtual space based on the target pose information; determine the position corresponding to the first pose information in virtual space, and create a virtual scanner at that position in combination with the imaging parameters; finally, use the virtual scanner to simulate anteroposterior image scanning in virtual space to generate virtual anteroposterior image data.

[0076] Optionally, after generating virtual anteroposterior image data, the system can also extract feature points corresponding to the three-dimensional model of the virtual surgical tool from the virtual anteroposterior image data to determine the two-dimensional position information of the three-dimensional model of the virtual surgical tool; and / or extract feature points corresponding to the virtual three-dimensional anatomical model from the virtual anteroposterior image data to determine the two-dimensional position information of the virtual three-dimensional anatomical model.

[0077] Step S505: Based on the error between the actual anteroposterior image data and the virtual anteroposterior image data, update the registration transformation matrix, and adjust the pose information of the virtual three-dimensional anatomical model and the virtual surgical tool based on the updated registration transformation matrix.

[0078] Optionally, the process of updating the registration transformation matrix can be as follows: The system can calculate the surgical area position error based on the deviation distance between the two-dimensional position information of the anatomical structure and the two-dimensional position information of the virtual three-dimensional anatomical model; and / or obtain the surgical tool position error based on the deviation distance between the two-dimensional position information of the surgical tool and the two-dimensional position information of the virtual surgical tool three-dimensional model; when the surgical area position error is greater than a first error value, and / or the surgical tool position error is greater than a second error value, it is determined that a system registration error exists; when a system registration error exists, the registration transformation matrix is ​​updated, and the pose information of the virtual three-dimensional anatomical model and the virtual surgical tool three-dimensional model is adjusted based on the updated registration transformation matrix.

[0079] Optionally, the registration transformation matrix is ​​updated, and the pose information of the virtual 3D anatomical model and the virtual surgical tool 3D model is adjusted based on the updated registration transformation matrix, as follows: The system can determine the correction amount based on the 3D coordinates of feature points in the rendered virtual surgical tool 3D model and the 2D position information of the surgical tool; or, it can determine the correction amount based on the 3D coordinates of feature points in the rendered virtual 3D anatomical model and the 2D position information of the anatomical structure; or, it can determine the correction amount based on the 3D coordinates of feature points in the rendered virtual surgical tool 3D model and the 3D coordinates of feature points in the rendered virtual 3D anatomical model, as well as the 2D position information of the surgical tool and the 2D position information of the anatomical structure; finally, the registration transformation matrix is ​​updated based on the correction amount, and the pose information of the virtual 3D anatomical model and the virtual surgical tool 3D model is adjusted based on the updated registration transformation matrix.

[0080] Optionally, the system can also use a timer to periodically output a positive-position film shooting prompt signal at preset fixed time intervals to prompt the operator to determine whether to perform the positive-position film shooting operation.

[0081] It should be noted that the various embodiments in this specification are described in a progressive manner, and the same or similar parts between the various embodiments can be referred to mutually. Each embodiment focuses on describing the differences from other embodiments. In particular, for the method embodiments, since they are basically similar to the system embodiments, the description is relatively simple, and the relevant parts can be referred to the description of the system embodiments. The system embodiments described above are merely illustrative, and the units described as separate components may or may not be physically separate. The components indicated as units may or may not be physical units, that is, they may be located in one place or distributed across multiple network units. Some or all of the modules can be selected to achieve the purpose of the solution in this embodiment according to actual needs. Those skilled in the art can understand and implement this without creative effort.

[0082] The above is merely one specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A medical navigation and positioning system, characterized in that, The system includes: an initial registration module, a scanning device, an optical tracker, surgical tools, a first data processing module, a final registration module, and a reference frame; The initial registration module is used to determine a registration transformation matrix based on the physical spatial pose relationship between multiple tracking targets and the optical tracker; the registration transformation matrix is ​​used to characterize the spatial transformation relationship between the coordinate systems of the multiple tracking targets and the optical tracking coordinate system, and the multiple tracking targets include the scanning device, the surgical tools, and the anatomical structure of the surgical area; The scanning device is used to perform an orthogonal image scan of the surgical area at a target time to obtain actual orthogonal image data; the actual orthogonal image data is used to describe the two-dimensional imaging features of the surgical instruments and the anatomical structure of the surgical area. The optical tracker is used to identify an infrared locator on the scanning device to obtain first pose information during the orthogonal image scanning, and to identify an infrared locator on the surgical tool to obtain second pose information, and to identify an infrared locator on the reference frame to obtain third pose information. The first data processing module is used to render a preset three-dimensional model of a virtual surgical tool and a virtual three-dimensional anatomical model of the surgical area in the virtual space corresponding to the optical tracking coordinate system based on the first pose information, the second pose information, the third pose information and the registration transformation matrix, and to simulate the orthogonal image scanning in the virtual space based on the imaging parameters of the scanning device to generate virtual orthogonal image data. The final registration module is used to update the registration transformation matrix based on the error between the actual orthogonal image data and the virtual orthogonal image data, and to adjust the pose information of the virtual three-dimensional anatomical model and the virtual surgical tool based on the updated registration transformation matrix.

2. The system according to claim 1, characterized in that, The reference frame is placed near the surgical area, and the infrared locator on the reference frame is a reflective patch array; the scanning device is also used for: Before performing the anteroposterior image scan, a three-dimensional image scan is performed on the surgical area to acquire three-dimensional anatomical image data of the surgical area; The optical tracker is also used for: During the three-dimensional image scanning process, the infrared locator on the scanning device is identified to obtain the first pose matrix, and the reflective array on the reference frame is identified to obtain the second pose matrix. Based on the first pose matrix and the second pose matrix, the first transformation matrix is ​​determined; The first transformation matrix is ​​used to characterize the spatial transformation relationship from the three-dimensional image coordinate system to the optical tracking coordinate system. The optical tracking coordinate system takes the position of the reflective patch array as its origin, and the three-dimensional image coordinate system takes the position of the infrared locator on the scanning device as its origin.

3. The system as recited in claim 2, wherein, The system also includes a robotic arm equipped with an infrared locator and an actuator, the actuator being located at the end of the robotic arm and connected to the surgical instrument; The optical tracker is also used for: During the movement of the robotic arm, an infrared positioner on the robotic arm is identified to obtain a third pose matrix; Based on the third pose matrix and the second pose matrix, the second transformation matrix is ​​determined; The second transformation matrix is ​​used to characterize the spatial transformation relationship from the robotic arm coordinate system to the optical tracking coordinate system, wherein the robotic arm coordinate system takes the position of the infrared positioner on the robotic arm as its origin.

4. The system as recited in claim 3, wherein, The system also includes a data acquisition module, used to acquire the rotation matrix and translation vector of the end effector relative to the robot arm coordinate system in multiple poses during the movement of the robot arm; The optical tracker is also used for: During the movement of the robotic arm, the infrared locator on the surgical tool is identified to obtain the pose of the tip of the surgical tool in the optical tracking coordinate system, thus obtaining a fourth pose matrix; The third transformation matrix is ​​determined using a tip calibration algorithm based on the fourth pose matrix, the rotation matrix, and the translation vector. The third transformation matrix is ​​used to characterize the spatial transformation relationship between the coordinate system of the tip of the surgical tool and the coordinate system of the robotic arm.

5. The system as recited in claim 4, wherein, The initial registration module is specifically used for: The registration transformation matrix is ​​determined based on the first transformation matrix, the second transformation matrix, and the third transformation matrix.

6. The system according to claim 5, characterized in that, The system further includes a second data processing module, which is specifically used for: Acquire the imaging parameters of the scanning device, the actual orthogonal image data, and the first pose information; Based on the imaging parameters of the scanning device, a perspective projection mapping relationship from the two-dimensional image plane to the three-dimensional image coordinate system is constructed; Based on the perspective projection mapping relationship, the first pose information and the actual orthogonal image data are mapped to three-dimensional space to construct a three-dimensional coordinate matrix; Based on the first transformation matrix, the three-dimensional coordinate matrix is ​​transformed into the optical tracking coordinate system to obtain the transformed coordinate matrix; Extract feature points of the surgical tool and / or feature points of the surgical area from the actual orthogonal image data; Based on the feature points of the surgical tool and the transformed coordinate matrix, the two-dimensional position information of the surgical tool is determined; And / or determine the two-dimensional position information of the anatomical structure based on the feature points of the anatomical structure and the transformed coordinate matrix.

7. The system as recited in claim 6, wherein, The first data processing module is specifically used for: The imaging parameters of the scanning device, the three-dimensional anatomical structure image data, the first pose information, the second pose information, the third pose information, and the registration transformation matrix are obtained. Based on the third pose information and the registration transformation matrix, the three-dimensional anatomical structure image data is converted into the optical tracking coordinate system to generate a virtual three-dimensional anatomical model, and the virtual three-dimensional anatomical model is rendered in the virtual space. Based on the registration transformation matrix, the second pose information is transformed into the robotic arm coordinate system, and the transformed second pose information is transformed into the optical tracking coordinate system to obtain the target pose information; A preset 3D model of a virtual surgical tool is invoked, and the 3D model of the virtual surgical tool is rendered in the virtual space based on the target pose information; In the virtual space, a position corresponding to the first pose information is determined, and a virtual scanner is created at that position in combination with the imaging parameters; Using the virtual scanner, the orthogonal image scanning is simulated in the virtual space to generate the virtual orthogonal image data.

8. The system of claim 7, wherein, The first data processing module is also used for: Feature points corresponding to the three-dimensional model of the virtual surgical tool are extracted from the virtual orthogonal image data to determine the two-dimensional position information of the three-dimensional model of the virtual surgical tool. And / or extract feature points corresponding to the virtual three-dimensional anatomical model from the virtual orthogonal image data to determine the two-dimensional position information of the virtual three-dimensional anatomical model.

9. The system as recited in claim 8, wherein, The final state registration module includes: an error determination unit and a registration unit; The error determination unit is used for: The positional error of the surgical area is calculated based on the deviation distance between the two-dimensional positional information of the anatomical structure and the two-dimensional positional information of the virtual three-dimensional anatomical model. And / or the deviation distance between the two-dimensional position information of the surgical tool and the two-dimensional position information of the three-dimensional model of the virtual surgical tool is used to obtain the position error of the surgical tool; The error determination unit is further configured to determine the existence of a system registration error when the position error of the surgical area is greater than a first error value, and / or the position error of the surgical tool is greater than a second error value. The registration unit is used for: When the system registration error exists, the registration transformation matrix is ​​updated, and the pose information of the virtual three-dimensional anatomical model and the virtual surgical tool three-dimensional model is adjusted based on the updated registration transformation matrix.

10. The system as recited in claim 9, wherein, The registration unit is specifically used for: Based on the three-dimensional coordinates of feature points in the rendered three-dimensional model of the virtual surgical tool and the two-dimensional position information of the surgical tool, the correction amount is determined; Alternatively, the correction amount can be determined based on the three-dimensional coordinates of feature points in the rendered virtual three-dimensional anatomical model and the two-dimensional position information of the anatomical structure. Alternatively, the correction amount can be determined based on the three-dimensional coordinates of feature points in the rendered virtual surgical tool 3D model and the three-dimensional coordinates of feature points in the rendered virtual 3D anatomical model, as well as the two-dimensional position information of the surgical tool and the two-dimensional position information of the anatomical structure. The registration unit is further used for: The registration transformation matrix is ​​updated based on the correction amount, and the pose information of the virtual three-dimensional anatomical model and the virtual surgical tool three-dimensional model is adjusted based on the updated registration transformation matrix.

11. The system of any one of claims 1-10, wherein, The system also includes a timer, which periodically outputs a positive-view film shooting prompt signal at preset fixed time intervals to prompt the operator to determine whether to perform the positive-view film shooting operation.

12. An automatic registration method for a navigation and positioning system, characterized in that, The method, applied to the medical navigation and positioning system according to any one of claims 1-11, comprises: Based on the physical spatial pose relationship between multiple tracking targets and the optical tracker, a registration transformation matrix is ​​determined; the registration transformation matrix is ​​used to characterize the spatial transformation relationship between the coordinate systems of the multiple tracking targets and the optical tracking coordinate system, wherein the multiple tracking targets include the scanning device, the surgical instruments, and the anatomical structure of the surgical area; An anteroposterior image scan is performed on the surgical area at a target time to obtain actual anteroposterior image data; the actual anteroposterior image data is used to describe the two-dimensional imaging features of the surgical instruments and the anatomical structure of the surgical area. During the orthogonal image scan, an infrared locator on the scanning device is identified to obtain first pose information, and an infrared locator on the surgical tool is identified to obtain second pose information, and an infrared locator on the reference frame is identified to obtain third pose information. Based on the first pose information, the second pose information, the third pose information, and the registration transformation matrix, a preset three-dimensional model of a virtual surgical tool and a virtual three-dimensional anatomical model of the surgical area are rendered in the virtual space corresponding to the optical tracking coordinate system. The anteroposterior image scanning is simulated in the virtual space according to the imaging parameters of the scanning device to generate virtual anteroposterior image data. Based on the error between the actual anteroposterior image data and the virtual anteroposterior image data, the registration transformation matrix is ​​updated, and the pose information of the virtual three-dimensional anatomical model and the virtual surgical tool is adjusted based on the updated registration transformation matrix.

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