Real-time femoral head center calculation method and device, surgical robot and storage medium

Abstract

The application relates to a femur head center real-time calculation method and device, a surgical robot and a storage medium, the method comprising the following steps: acquiring real-time position coordinates of a pelvis target point and a femur head target point; when the acquisition frequencies of the pelvis target point and the femur head target point are consistent, calculating a position transformation relationship between a current time and a preset time of the pelvis target point according to the real-time position coordinates of the pelvis target point; and determining a second position coordinate of the femur head target point at the current time after correction according to a first position coordinate in the real-time position coordinates of the femur head target point at the current time and the position transformation relationship. Through the application, the accuracy of a femur center positioning algorithm is improved, and the effect of real-time positioning of the femur center is achieved.

Description

Technical Field

[0001] This application relates to the field of medical technology, and in particular to a method, apparatus, surgical robot, and storage medium for real-time calculation of the femoral head center. Background Technology

[0002] With the continuous advancement of modern medicine and the widespread application of advanced achievements from various disciplines, surgical procedures have made significant progress in reducing patient suffering and minimizing surgical incisions. In surgeries involving the calculation of the femoral center of the hip joint, the location of the femoral center is crucial for preoperative planning and intraoperative navigation, providing essential guidance for various functional indicators. For instance, determining the location of the femoral center is a prerequisite for calculating lower limb length and joint offset.

[0003] Preoperative planning can determine the location of the femoral center by acquiring image data of the hip region using medical imaging equipment (such as CT or MRI), and then using the physical appearance of the femoral head combined with mathematical calculations, with the aid of a computer, the femoral center location can be obtained relatively accurately. However, for intraoperative navigation, which requires calculating the location of the femoral center in a clinical setting, medical imaging methods are generally insufficient. Therefore, an effective and feasible alternative method must be found to accurately locate the rotation center of the femur. Summary of the Invention

[0004] This application provides a method, apparatus, surgical robot, and storage medium for real-time calculation of the femoral head center, to at least solve the problem of inaccurate positioning of the femoral head center in intraoperative navigation in related technologies.

[0005] In a first aspect, embodiments of this application provide a method for real-time calculation of the femoral head center, including:

[0006] Obtain the real-time position coordinates of the target points on the pelvis and the femoral head;

[0007] The positional transformation of the pelvis between the current time and the preset time is calculated based on the real-time position coordinates of the target point of the pelvis.

[0008] Based on the first position coordinate of the femoral head target point at the current time in the real-time position coordinates and the position transformation relationship, determine the second position coordinate of the femoral head target point at the current time after correction of the first position coordinate;

[0009] The rotation center of the femoral head at the current moment is calculated based on the second position coordinates of the target point of the femoral head.

[0010] In some embodiments, when the acquisition frequencies of the pelvic target point and the femoral head target point are inconsistent, after obtaining the real-time position coordinates of the pelvis and femur, a coordinate synchronization step is also included:

[0011] Obtain the real-time position coordinates of the femoral head target point and the corresponding first-time information in the first-time coordinate system;

[0012] Based on the first time information, obtain the second time information corresponding to the pelvic target point in the second time coordinate system;

[0013] Based on the first time information, the second time information, and the position coordinates of the pelvic target point under the second time information, determine the real-time position coordinates of the pelvic target point and the femoral head target point under the first time information;

[0014] The real-time position coordinates of the pelvic target point and the femoral head target point under the first time information are updated to the real-time position coordinates of the pelvic target point.

[0015] In some embodiments, calculating the positional change relationship of the pelvis between the current time and a preset time based on the real-time position coordinates of the pelvic target point includes:

[0016] Calculate the centroid of the pelvic tracking target point at the preset time and the current time, respectively;

[0017] The offset matrix of the tracking target point is determined based on the centroid of the tracking target point at the current time and the position coordinates of each tracking target point at the preset time and the current time.

[0018] Based on the offset matrix of the tracking target point and the position coordinates of the tracking target point at the current time and the preset time, the position transformation relationship of the pelvic target point between the current time and the preset time is determined.

[0019] In some embodiments, calculating the rotation center of the femoral head at the current moment based on the second position coordinates of the femoral head target point includes:

[0020] Select at least four femoral head target points within the time period determined by the current time and the initial time.

[0021] The sample point set is determined based on the second position coordinates of at least four femoral head target points;

[0022] The rotation center of the femoral head at the current moment is calculated based on the set of sample points.

[0023] In some embodiments, calculating the rotation center of the femoral head at the current moment based on the second position coordinates of the femoral head target point includes:

[0024] The set of sample points is determined based on the second position coordinates of at least four non-coplanar femoral head target points;

[0025] Based on the multiple sets of sample points, multiple potential rotation centers corresponding to the femoral center at the current moment are calculated;

[0026] Based on the position coordinates corresponding to the multiple potential rotation centers and the preset outlier metric threshold, a first type of interior point is determined among the multiple potential rotation centers;

[0027] Based on the first type of in-point, determine the rotation center of the femur at the current moment.

[0028] In some embodiments, determining the rotation center of the femoral center at the current moment based on the first in-class point includes:

[0029] When the number of points within the first class is greater than the preset threshold for the number of points within the first class, the average coordinates of multiple points within the first class are calculated.

[0030] Based on the position coordinates corresponding to the potential rotation centers, the mean coordinates, and the outlier metric threshold, a second type of interior point is determined among the multiple potential rotation centers;

[0031] When the number of second-class inliers equals the preset threshold for the number of second-class inliers, the mean coordinates of all second-class inliers are determined as the rotation center of the femoral head at the current moment.

[0032] In some embodiments, it also includes:

[0033] Calculate the standard deviation and residuals based on the rotation center at multiple time points;

[0034] The standard deviation and residuals are compared with preset standard deviation thresholds and residual thresholds, respectively, to determine whether the data collection is sufficient based on the comparison results.

[0035] Secondly, embodiments of this application provide a real-time calculation device for the femoral head center, comprising:

[0036] The real-time coordinate acquisition unit is used to acquire the real-time position coordinates of the pelvic target point and the femoral head target point;

[0037] The position transformation relationship acquisition unit calculates the position transformation relationship between the pelvis at the current time and the preset time based on the real-time position coordinates of the pelvis target point when the acquisition frequencies of the pelvis target point and the femoral head target point are consistent.

[0038] The correction unit is used to determine the corrected second position coordinates of the femoral head target point at the current time based on the first position coordinates of the femoral head target point in the real-time position coordinates at the current time and the position transformation relationship;

[0039] The rotation center calculation unit is used to calculate the rotation center of the femoral head at the current moment based on the second position coordinates of the femoral head target point.

[0040] Thirdly, embodiments of this application provide a surgical robot, including a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, it implements the real-time calculation method for the femoral head center as described in the first aspect above.

[0041] Fourthly, embodiments of this application provide a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the real-time calculation method for the femoral head center as described in the first aspect above.

[0042] Compared to related technologies, the real-time calculation method for the femoral head center provided in this application simultaneously tracks pelvic and femoral data. It calculates the positional transformation relationship between the pelvic target point and a preset time based on the real-time position coordinates of the pelvic target point, thereby obtaining the transformation matrix of the pelvis between any current time and the preset time. By determining the corrected second position coordinates of the femoral head target point at the current time based on the first position coordinate in the real-time position coordinates of the femoral head target point at the current time and the positional transformation relationship, it achieves the correction of the position coordinates of the femoral head target point through the transformation matrix of the pelvis between any current time and the preset time. This solves the translational error introduced by factors such as vibration and patient posture changes during surgical operations and corrects it accordingly, thereby improving the accuracy of the femoral head center positioning algorithm. Simultaneously, during femoral rotation, the rotation center of the femoral head at the current time is calculated in real-time based on the generated pelvic and femoral data, and the position of the femoral head center is continuously updated as the movement progresses, achieving real-time femoral head center positioning.

[0043] Details of one or more embodiments of this application are set forth in the following drawings and description to make other features, objects and advantages of this application more readily apparent. Attached Figure Description

[0044] The accompanying drawings, which are included to provide a further understanding of this application and form part of this application, illustrate exemplary embodiments of this application and are used to explain this application, but do not constitute an undue limitation of this application. In the drawings:

[0045] Figure 1 This is a flowchart illustrating a real-time calculation method for the femoral head center in one embodiment of this application.

[0046] Figure 2 This is a flowchart illustrating a real-time calculation method for the femoral head center in another embodiment of this application;

[0047] Figure 3 This is a flowchart illustrating the calculation of position transformation relationships in one embodiment of this application;

[0048] Figure 4 This is a schematic diagram of the process for calculating the center of rotation of the femoral head at the current moment in one embodiment of this application;

[0049] Figure 5 This is a flowchart illustrating the process of calculating the center of rotation of the femoral head at the current moment in another embodiment of this application;

[0050] Figure 6 This is a flowchart illustrating the calculation of the center of rotation of the femoral head at the current moment in another embodiment of this application;

[0051] Figure 7 This is a structural block diagram of a real-time computing device for the femoral head center in one embodiment of this application;

[0052] Figure 8 This is a schematic diagram of the surgical robot in one embodiment of this application.

[0053] Figure descriptions: 701, Real-time coordinate acquisition unit; 702, Position transformation relationship acquisition unit; 703, Correction unit; 704, Rotation center acquisition unit; 80, Bus; 81, Processor; 82, Memory; 83, Communication interface. Detailed Implementation

[0054] To make the objectives, technical solutions, and advantages of this application clearer, the application is described and illustrated below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application. All other embodiments obtained by those skilled in the art based on the embodiments provided in this application without inventive effort are within the scope of protection of this application.

[0055] Obviously, the accompanying drawings described below are merely some examples or embodiments of this application. Those skilled in the art can apply this application to other similar scenarios based on these drawings without any inventive effort. Furthermore, it is understood that although the efforts made in this development process may be complex and lengthy, for those skilled in the art related to the content disclosed in this application, any changes to design, manufacturing, or production based on the technical content disclosed in this application are merely conventional technical means and should not be construed as insufficient disclosure of the content of this application.

[0056] In this application, the reference to "embodiment" means that a specific feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment that is mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described in this application may be combined with other embodiments without conflict.

[0057] Unless otherwise defined, the technical or scientific terms used in this application shall have the ordinary meaning understood by one of ordinary skill in the art to which this application pertains. The terms “a,” “an,” “an,” “the,” and similar words used in this application do not indicate quantity limitation and may indicate singular or plural. The terms “comprising,” “including,” “having,” and any variations thereof used in this application are intended to cover non-exclusive inclusion; for example, a process, method, system, product, or device that includes a series of steps or modules (units) is not limited to the listed steps or units, but may also include steps or units not listed, or may include other steps or units inherent to these processes, methods, products, or devices. The terms “connected,” “linked,” “coupled,” and similar words used in this application are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. “Multiple” used in this application refers to two or more. “And / or” describes the relationship between related objects, indicating that three relationships may exist; for example, “A and / or B” can represent: A alone, A and B simultaneously, and B alone. The character " / " generally indicates that the preceding and following objects are in an "or" relationship. The terms "first," "second," and "third" used in this application are merely to distinguish similar objects and do not represent a specific ordering of the objects.

[0058] With the continuous development of medical theory, rapidly advancing medical imaging, image processing, and robotics technologies are increasingly being applied to the medical field. Navigation systems have become an indispensable component, widely used in neurosurgery, plastic surgery, orthopedics, and otolaryngology. Surgical navigation systems accurately establish the registration relationship between medical imaging data, surgical targets, and surgical instruments. Through appropriate coordinate transformations, they control surgical tools to reach designated locations, thereby enabling the implementation of corresponding surgical procedures. This is of great significance for improving surgical positioning accuracy, reducing surgical trauma, optimizing surgical pathways, and increasing surgical success rates.

[0059] The real-time calculation method for the femoral head center provided in this embodiment can be applied to surgical scenarios where intraoperative navigation requires reference to the mechanical axis of the lower limb or the center point of the femoral head, such as total knee arthroplasty, hip replacement surgery, high tibial osteotomy, lower limb femoral deformity correction, tibial deformity correction, and lower limb femoral and tibial fracture surgery. This application is not limited to scenarios such as locating the femoral center.

[0060] This embodiment also provides a method for real-time calculation of the femoral head center. Figure 1 This is a flowchart of a real-time calculation method for the femoral head center according to an embodiment of this application, such as... Figure 1 As shown, the process includes the following steps:

[0061] Step S101: Obtain the real-time position coordinates of the pelvic target point and the femoral head target point.

[0062] Generally, during intraoperative navigation, when the surgeon rotates the femur of the surgical target, the pelvis will inevitably move slightly during the rotation due to factors such as vibration and changes in posture. Once the pelvis moves slightly, it will inevitably introduce a small amount of offset during the femoral position tracking process, resulting in an error in the positioning of the femoral head center.

[0063] In this embodiment, the position coordinates of the pelvis and femur are tracked synchronously, and the real-time position coordinates of the pelvic target point and the femoral head target point are acquired simultaneously for real-time calculation of the femoral center. In some embodiments, the real-time position coordinates of the pelvic target point and the femoral head target point can be acquired through a femoral surface locator, a femoral tracer, or an optical tracking device; this application is not limited thereto. For example, an optical navigator can be used to track a tracking array fixed to the pelvis and femur to acquire their respective real-time positions. The pelvic target point is the target point that needs to be tracked in the surgical pelvic region, and the femoral head target point is the target point that needs to be tracked in the surgical femoral region.

[0064] Step S102: Calculate the positional transformation relationship of the pelvis between the current time and the preset time based on the real-time position coordinates of the pelvic target point.

[0065] In this embodiment, the pelvic target point and femoral head target point of the surgical target can be acquired synchronously or asynchronously. Synchronous acquisition means that data is acquired simultaneously at the same frequency; asynchronous acquisition means that data is acquired simultaneously but at different frequencies. For example, two cameras can be used to simultaneously acquire the pelvic target point and the femoral head target point, resulting in different acquisition frequencies due to the different fixed sampling frequencies of the two cameras. When the pelvic target point and the femoral head target point are acquired synchronously, their acquisition frequencies are consistent, and calculations can be performed directly based on their position coordinates. There is at least one femoral head target point.

[0066] In this embodiment, to further eliminate the negative impact of pelvic translation and rotation on femoral center positioning during femoral rotation, the position and orientation of the pelvis are tracked based on the real-time position coordinates of the pelvic target point. Specifically, based on the real-time position coordinates of the pelvic target point, the position transformation relationship of the pelvis between the current time and a preset time is calculated, and then the real-time position of the pelvis is tracked using the position transformation relationship. It should be noted that, in order to calculate the position transformation relationship of the pelvic target point between the current time and the preset time, there must be at least three pelvic target points, and at least three points must be non-collinear.

[0067] Step S103: Based on the first position coordinate of the femoral head target point at the current time (i.e., the first position coordinate of the femoral head target point at the current time) in the real-time position coordinates of the femoral head target point and the position transformation relationship, determine the second position coordinate of the first position coordinate of the femoral head target point at the current time after correction.

[0068] In this embodiment, after obtaining the positional transformation relationship of the pelvis between the current time and a preset time, the first position coordinates of the femoral head target point at the current time can be corrected according to the first position coordinates of the femoral head target point at the current time and the positional transformation relationship, thus obtaining the corrected second position coordinates of the femoral head target point. Specifically, the first position coordinates of the femoral head target point at any current time can be substituted into the positional transformation relationship to obtain the corrected second position coordinates of the femoral head target point at the corresponding time.

[0069] Through the above steps, during surgical navigation, the position coordinates of the pelvic target point are tracked in real time, the real-time position change relationship of the pelvis between the current time and the preset time is calculated, and the position coordinates of the femoral head target point are corrected in real time according to the position change relationship, thus realizing the real-time correction of the femoral position coordinates.

[0070] Step S104: Calculate the rotation center of the femoral head at the current moment based on the second position coordinates of the femoral head target point.

[0071] In this embodiment, without the aid of medical imaging, the calculation of the femoral rotation center based on the corrected second position coordinates yields a more accurate result. The calculation of the rotation center based on the second position coordinates of the femoral head target point can employ existing techniques in the art, such as using Cramer's rule to establish a system of equations based on the second position coordinates of four non-coplanar femoral head target points to calculate the center coordinates of the sphere. This will not be elaborated upon further in this application.

[0072] In summary, the real-time femoral head center calculation method provided in this application simultaneously tracks pelvic and femoral data, calculates the position transformation relationship between the pelvic target point and a preset time based on the real-time position coordinates of the pelvic target point, and thus obtains the transformation matrix of the pelvis between any current time and the preset time. By determining the corrected second position coordinates of the femoral head target point at the current time based on the first position coordinate in the real-time position coordinates of the femoral head target point at the current time and the position transformation relationship, the method corrects the position coordinates of the femoral head target point using the transformation matrix of the pelvis between any current time and the preset time. This solves the translational error introduced by factors such as vibration and changes in patient posture during the surgical operation of the femur, and corrects it accordingly, thereby improving the accuracy of the femoral head center positioning algorithm. Simultaneously, during femoral rotation, the rotation center of the femoral head at the current time is calculated in real-time based on the generated pelvic and femoral data, and the position of the femoral head center is continuously updated as the movement progresses, achieving the effect of real-time femoral head center positioning.

[0073] The embodiments of this application will be described and illustrated below through preferred embodiments.

[0074] This embodiment also provides a method for real-time calculation of the femoral head center. Figure 2 This is a flowchart of another real-time calculation method for the femoral head center according to an embodiment of this application, such as... Figure 2 As shown, the process includes the following steps:

[0075] Step S201: Obtain the real-time position coordinates of the pelvic target point and the femoral head target point;

[0076] Step S202: When the acquisition frequencies of the pelvic target point and the femoral head target point are inconsistent, the real-time position coordinates of the femoral head target point are obtained, and the corresponding first time information in the first time coordinate system is obtained.

[0077] Step S203: Based on the first time information, obtain the second time information corresponding to the pelvic target point in the second time coordinate system;

[0078] Step S204: Based on the first time information, the second time information, and the position coordinates of the pelvic target point under the second time information, determine the real-time position coordinates of the pelvic target point and the femoral head target point under the first time information.

[0079] Step S205: Update the real-time position coordinates of the pelvic target point and the femoral head target point under the first time information to the real-time position coordinates of the pelvic target point.

[0080] Step S206: Calculate the positional transformation relationship of the pelvis between the current time and the preset time based on the real-time position coordinates of the pelvic target point;

[0081] Step S207: Based on the first position coordinates of the femoral head target point in the real-time position coordinates at the current time and the position transformation relationship, determine the second position coordinates of the femoral head target point after correction at the current time;

[0082] Step S208: Calculate the rotation center of the femoral head at the current moment based on the second position coordinates of the femoral head target point.

[0083] In this embodiment, the implementation principle and technical effect of steps S201, S206-S208 are the same as those in the above embodiments. For the sake of brevity, any parts not mentioned in this embodiment can be referred to the corresponding content in the above embodiments.

[0084] In this embodiment, when the pelvic target point and the femoral head target point of the surgical target are acquired asynchronously, the acquisition frequencies of the pelvic target point and the femoral head target point are inconsistent. After obtaining the real-time position coordinates of the pelvis and the femur, a coordinate synchronization step is also included: according to the first time information corresponding to the femoral head target point in the first time coordinate system and the second time information corresponding to the pelvic target point in the second time coordinate system, the position coordinates of the femoral head target point and the position coordinates of the pelvic target point are mapped to the same time coordinate system.

[0085] For example, when the acquisition frequencies of the pelvic target point and the femoral head target point are inconsistent, the acquisition of the femoral head target point is defined as being in a first time coordinate system, and the acquisition of the pelvic target point is defined as being in a second time coordinate system. The coordinate synchronization steps then include: firstly, obtaining the first time information corresponding to the real-time position coordinates of the femoral head target point in the first time coordinate system, where the first time coordinate system is the time coordinate system under the acquisition frequency of the femoral head target point, and the first time information is the acquisition time of the femoral head target point in the first time coordinate system.

[0086] Then, based on the first time information, the second time information corresponding to the pelvic target point in the second time coordinate system is obtained. The second time coordinate system is a time coordinate system based on the acquisition frequency of the pelvic target point. The time interval in the second time coordinate system is different from that in the first time coordinate system, and the data in the first time coordinate system and the second time coordinate system are acquired asynchronously. The second time information is the associated time determined based on the first time information. Optionally, in some embodiments, the first time information can be determined as a time point in the first time coordinate system, and the second time information can be determined as two time points adjacent to the first time information in the second time coordinate system. Taking points at positions adjacent to the first time information can improve the accuracy of subsequent real-time position coordinate calculation. In other embodiments, when the acquisition frequency of the pelvic target point and the femoral head target point remains stable, the real-time position coordinate can be calculated based on two time points in the second time coordinate system that are not adjacent to the first time information. In this case, the first time information can be determined as a time point in the first time coordinate system, and the second time information can be determined as two time points in the second time coordinate system that are not adjacent to the first time information. In other embodiments, the first time information can be a single point in time within a first time coordinate system, and the second time information can be multiple points in a second time coordinate system adjacent to the first time information. By repeatedly iterating through multiple available points to calculate the average, the accuracy of the calculation results can be improved. It is understood that, to achieve batch point selection, when the first time information is a series of points in the first time coordinate system, the second time information includes multiple points in the second time coordinate system adjacent to the first time information; this application does not impose specific limitations on this.

[0087] Next, based on the first time information, the second time information, and the position coordinates of the pelvic target point under the second time information, the real-time position coordinates of the pelvic target point corresponding to the femoral head target point under the first time information are determined. Specifically, based on the first time information, the second time information, and the position coordinates of the pelvic target point under the second time information, linear interpolation or data fitting can be used to obtain the real-time position coordinates of the pelvic target point corresponding to the femoral head target point under the first time information, and these coordinates are then updated synchronously to the real-time position coordinates of the pelvic target point.

[0088] In one specific implementation, the method for determining the real-time position coordinates of the pelvic target point and the femoral head target point under the first time information using linear interpolation is as follows:

[0089] Let the acquisition time of the femoral head target point be the first time coordinate system, and obtain the first time information based on the first time coordinate system; let the acquisition time of the pelvic target point be the second time coordinate system, and obtain the second time information based on the second time coordinate system. Let the real-time position coordinates of the pelvic target point at time i be {X... pi ,Y pi Z pi}, the real-time position coordinates of the femoral head target point at time i are {X fi ,Y fi Z fi}, where X, Y, and Z are the position coordinates of the data on the X, Y, and Z axes, respectively. Let the first time information corresponding to the real-time position coordinates of the femoral head target point in the first time coordinate system be k, and the second time information determined based on the first time information be [k] and [k+1]. The real-time position coordinates of the pelvic target point under the second time information [k] are {X... p[k] ,Y p[k] Z p[k] The real-time position coordinates of the pelvic target point under the second time information [k+1] are {Xp}. [k+1] ,Yp [k+1] ,Zp [k+1]}, then the real-time position coordinates {X} of the pelvic target point and the femoral head target point under the first time information k. pk ,Y pk Z pk}for:

[0090] X pk =([k+1]–k)*X p[k] +(k–[k])*X p[k+1]

[0091] Y pk =([k+1]–k)*Y p[k] +(k–[k])*Y p[k+1]

[0092] Z pk =([k+1]–k)*Z p[k] +(k–[k])*Z p[k+1]

[0093] Where [k] represents the nearest forward time from time k when there is data in the pelvis in the second time coordinate system.

[0094] It is understood that in other embodiments, other methods such as spline interpolation, kriging interpolation, discrete smoothing interpolation, and trend surface smoothing interpolation can be used to map the position coordinates of the femoral head target point and the position coordinates of the pelvic target point to the same time coordinate system. This application does not make specific limitations here.

[0095] Through the above steps, when the acquisition frequencies of the pelvic target point and the femoral head target point are inconsistent, the pelvic target point and the femoral head target point can be acquired asynchronously. Based on the real-time position coordinates obtained by asynchronous acquisition, the rotation center of the femoral head at the current moment can be calculated, which improves the ease of use of the algorithm and broadens the application scenarios.

[0096] like Figure 3 As shown, based on the above embodiments, in some embodiments, calculating the positional transformation relationship of the pelvis between the current time and a preset time based on the real-time position coordinates of the pelvic target point includes:

[0097] Step S301: Calculate the centroid of the pelvic tracking target point at the preset time and the current time, respectively.

[0098] Specifically, in some embodiments, the centroid of the target point being tracked at a preset time is C1, and the centroid of the target point being tracked at the current time is C. i The centroid of the tracking target point can be calculated using the following formula:

[0099]

[0100] Where n is the sequence number of the target point being tracked, and N is the total number of target points being tracked. The target points being tracked include at least three non-collinear target points along the pelvis. Let P = [x, y, z] be the transpose of the coordinates of the nth tracking target point at time i. T .

[0101] Step S302: Determine the offset matrix of the tracking target point based on the centroid of the tracking target point at the current time and the position coordinates of each tracking target point at the preset time and the current time.

[0102] Specifically, in this embodiment, based on the centroid of the tracking target point at the current time and the position coordinates of each tracking target point at the preset time and the current time, the covariance matrix H corresponding to the coordinates of the tracking target points at the current time and the preset time is determined:

[0103]

[0104] Then, singular value decomposition is performed on the above covariance matrix H:

[0105] [USV] = SVD(H)

[0106] SVD refers to Singular Value Decomposition, an important matrix decomposition method in linear algebra. USV consists of three matrices obtained after Singular Value Decomposition: U is the left singular matrix, V is the right singular matrix, and the elements on the main diagonal of matrix S are the singular values.

[0107] The rotation matrix R for tracking the target point is:

[0108] R = VU T

[0109] The translation matrix T for tracking the target point is:

[0110] T = -R*C1 + C i

[0111] From the above, we can obtain the offset matrix M of the pelvic tracking target point. K =[R,T].

[0112] Step S303: Based on the offset matrix of the tracking target point and the position coordinates of the tracking target point at the current time and the preset time, determine the position transformation relationship of the pelvic target point between the current time and the preset time.

[0113] Specifically, based on the rotation matrix R, translation matrix T, and position coordinates of the target point at the current moment... and position coordinates relative to the preset time The positional transformation of the pelvic target point between the current time and the preset time is obtained as follows:

[0114]

[0115] Of course, in other embodiments, the calculation methods for the centroid, rotation matrix, and translation matrix of the target point are not limited to this, and this application does not limit them here.

[0116] Through the above steps S301-S303, the feature matrix of the negative impact of pelvic translation and rotation on the subsequent femoral head center positioning can be calculated. The positional transformation relationship between the pelvic target point at the current time and the preset time can be used to eliminate the influence of pelvic movement on femoral rotation and improve the accuracy of the algorithm.

[0117] like Figure 4 As shown, based on the above embodiments, in some embodiments, calculating the rotation center of the femoral head at the current moment according to the second position coordinates of the femoral head target point includes:

[0118] Step S401: Select at least four femoral head target points within the time period determined by the current time and the initial time.

[0119] Step S402: Determine the sample point set based on the second position coordinates of at least four femoral head target points;

[0120] Step S403: Calculate the rotation center of the femoral head at the current moment based on the set of sample points.

[0121] In this embodiment, the theoretical basis for calculating the coordinates of the sphere's center is that a sphere can be uniquely determined by four non-coplanar points in space. In some embodiments, the initial time is set to 0, and the current time is set to T. current In time 0-T current Four non-coplanar femoral head target points are randomly selected within the sphere to calculate the coordinates of the sphere's center. In other embodiments, to improve the representativeness of the extracted points, the time interval 0-T can be used. current The process is divided into at least two time periods, and within each time period, a target point on the femoral head is selected for calculating the coordinates of the center of rotation. More preferably, the process can be divided into four time periods, and within each time period, at least one target point on the femoral head is selected for calculating the coordinates of the center of rotation. It is understood that the time periods can be divided evenly or unevenly, and this application does not impose any limitations on this. The calculation of the center of rotation coordinates based on four non-coplanar target points on the femoral head can employ existing methods, which will not be elaborated upon here. Through the above steps, the rotation center of the femoral head at the current moment can be calculated; this method is simple, easy to implement, and has low algorithm complexity.

[0122] like Figure 5 As shown, based on the above embodiments, in some embodiments, calculating the rotation center of the femoral head at the current moment according to the second position coordinates of the femoral head target point includes:

[0123] Step S501: Determine the set of sample points based on the second position coordinates of at least four non-coplanar femoral head target points.

[0124] Step S502: Based on the multiple sets of sample points, calculate the multiple potential rotation centers corresponding to the femoral center at the current moment.

[0125] In this embodiment, to further improve the positioning accuracy of the femoral center, the rotation center is calculated using multiple sample point sets. Specifically, multiple potential rotation centers are obtained as candidate points by iterative calculation based on the multiple sample point sets. The acquisition of the sample point sets and the calculation of the potential rotation centers are the same as in the above embodiment, and will not be repeated here.

[0126] Step S503: Based on the position coordinates corresponding to the multiple potential rotation centers and a preset outlier metric threshold, determine the first type of interior point among the multiple potential rotation centers.

[0127] Step S504: Determine the rotation center of the femur at the current moment based on the first type of in-point.

[0128] Specifically, in this embodiment, any number of potential rotation centers can be selected and averaged to obtain the mean center coordinates. Then, the characteristic distances between all potential rotation centers and the mean center coordinates are calculated. Potential rotation centers whose characteristic distance calculation results are less than a preset outlier threshold are identified as first-class inliers. In one specific implementation, let there be n potential rotation centers and a preset outlier threshold of t. Then, m potential rotation centers are selected from the n potential rotation centers, and the average of the X, Y, and Z coordinates of each of the m potential rotation centers is calculated to obtain the mean center coordinates C. Then, the first-class inliers are selected based on the outlier threshold t. Specifically, the characteristic distances between all n potential rotation centers and the mean center coordinates C are calculated. Whenever the characteristic distance between a potential rotation center and the mean center coordinates C is less than the preset outlier threshold t, the potential rotation center is identified as a first-class inlier.

[0129] In this embodiment, the rotation center is calculated based on the first type of interior points. The specific calculation method can be to directly obtain the rotation center at the current moment by taking the average value, or to calculate the rotation center after further data filtering based on the first type of interior points. This embodiment does not limit the calculation method.

[0130] Through the above steps S501-S504, when calculating the rotation center, by determining whether the potential rotation center is a first-class inland point, it is possible to verify and determine whether the potential rotation center is suitable. By calculating the rotation center based on the first-class inland point, some measurement anomalies caused by human factors in the potential rotation center points can be eliminated, reducing the adverse effects of these anomalies and improving the calculation accuracy.

[0131] Based on the above embodiments, in some embodiments, step S504 includes:

[0132] When the number of inliers of the first class is greater than a preset threshold for the number of inliers of the first class, the mean coordinates of multiple inliers of the first class are calculated; based on the position coordinates corresponding to the potential rotation center, the mean coordinates, and the outlier metric threshold, a second inlier of the second class is determined among multiple potential rotation centers; when the number of inliers of the second class is equal to a preset threshold for the number of inliers of the second class, the mean coordinates of all inliers of the second class are determined as the rotation center of the femoral head at the current moment.

[0133] In this embodiment, a second type of interior point can be further determined based on the potential rotation center and the first type of interior points. Specifically, when the number of the first type of interior points is greater than a preset threshold for the number of the first type of interior points, the average coordinates of the positions of the first type of interior points are taken to obtain the mean coordinates. Then, the feature distance between all the potential rotation centers and the mean coordinates is calculated, and the potential rotation centers whose calculation results are less than a preset outlier metric threshold are determined as the second type of interior points. Finally, when the number of the second type of interior points is equal to the preset threshold for the number of the second type of interior points, the mean coordinates of all the second type of interior points are determined as the rotation center of the femoral head at the current moment. By calculating the rotation center based on the second type of interior points further determined based on the potential rotation centers and the first type of interior points, unsuitable points in the candidate points of the rotation center calculation formula can be further eliminated, improving the calculation accuracy.

[0134] For example, in one specific implementation, based on the position coordinates corresponding to the potential rotation centers, the mean coordinates, and the outlier metric threshold, a second type of interior point is determined among multiple potential rotation centers: Let the preset outlier metric threshold be t, and the first type of interior point count threshold be T. Then, when the number of first type of interior points is greater than the first type of interior point count threshold T, the average of the X, Y, and Z coordinates of the T interior points is taken to calculate the mean coordinate point C'. Then, the characteristic distance between each potential rotation center and the mean sphere center coordinate point C' is calculated. Whenever the characteristic distance between a potential rotation center and the mean sphere center coordinate point C' is less than the preset outlier metric threshold t, the potential rotation center is determined as a second type of interior point.

[0135] like Figure 6 As shown, based on the above embodiments, some embodiments further include:

[0136] Step S505: When the number of points in the second category is greater than the preset threshold for the number of points in the second category, update the threshold for the number of points in the second category to the current number of points in the second category.

[0137] Step S506: Repeat the steps for determining the first class interior points and the second class interior points until the preset number of iterations is reached;

[0138] Step S507: Determine the mean coordinates of all intraclass points corresponding to the preset number of iterations as the rotation center of the femoral center at the current moment.

[0139] In this embodiment, the rotation center at the current moment can be iteratively calculated to further improve the calculation accuracy. Specifically, a preset number of iterations iter is set, and the threshold value maxT of the number of the second type of inliers is initialized to 0. When the number of the second type of inliers is greater than the threshold value maxT of the second type of inliers, maxT is updated, and the threshold value of the number of the second type of inliers is updated to the current number of the second type of inliers, and the count value of the number of iterations is incremented by 1. The steps of determining the first type of inliers and the second type of inliers are repeated iteratively until the preset number of iterations is reached, at which point it is determined that the data iterative calculation is sufficient and the calculation result can meet the accuracy requirements. At this time, the mean coordinates of all inliers are calculated, and this mean coordinate is determined as the rotation center of the femoral head at the current moment.

[0140] Based on the above embodiments, in some of these embodiments, the following steps are further included:

[0141] Calculate the standard deviation and the residual based on the rotation centers at multiple moments, and compare the standard deviation and the residual with the preset standard deviation threshold and residual threshold respectively, so as to determine whether the data acquisition is sufficient according to the comparison result.

[0142] In this embodiment, during the movement of the femoral head, the position coordinates of the pelvis and the femur are synchronously tracked and the rotation center of the femoral head is calculated in real time. After calculating the rotation centers at multiple moments, it is necessary to further determine whether the data acquisition is sufficient, so as to give a suggestion on whether to continue the movement according to the judgment result. Specifically, the rotation centers at multiple moments can be calculated first by using the above real-time calculation method of the femoral head center, and the standard deviation and the residual are calculated based on the rotation centers at multiple moments, and the standard deviation and the residual are compared with the preset standard deviation threshold and residual threshold respectively. When the calculated standard deviation is less than the preset standard deviation threshold and the residual is less than the preset residual threshold, it is determined that the data acquisition is already sufficient and the surgical target does not need to continue the movement; otherwise, it is determined that the data acquisition is not sufficient and the surgical target needs to continue the movement to obtain more data for the calculation of the femoral head center. By determining whether the data acquisition is sufficient, a suggestion on whether to continue the operation can be further given, and the calculation result can be timely feedback to the user.

[0143] In a specific implementation manner, a preset standard deviation threshold Ts and a residual threshold Td are set. First, obtain the rotation center of the femoral head at a total of k moments between the current moment and the preset moment , and calculate the standard deviation S i： where the value range of k is 1 < k ≤ i. Then calculate the residual based on the rotation centers of the femoral head at the current moment and the previous moment If both S i < T s and D i < T dWhen the time is right, it is determined that the data acquisition is sufficient, and the movement will stop. The coordinates of the rotation center at this point will then be output. Otherwise, it is determined that exercise needs to continue.

[0144] It should be noted that the steps shown in the above process or in the flowchart of the accompanying figures can be executed in a computer system such as a set of computer-executable instructions, and although a logical order is shown in the flowchart, in some cases the steps shown or described may be executed in a different order than that shown here.

[0145] This embodiment also provides a real-time calculation device for the femoral head center, which is used to implement the above embodiments and preferred embodiments, and will not be repeated as described above. As used below, the terms "module," "unit," "subunit," etc., can refer to a combination of software and / or hardware that performs a predetermined function. Although the device described in the following embodiments is preferably implemented in software, hardware implementation, or a combination of software and hardware, is also possible and contemplated.

[0146] Figure 7 This is a structural block diagram of the real-time computing device for the femoral head center according to an embodiment of this application, such as... Figure 7 As shown, the device includes: a real-time coordinate acquisition unit 701, a position transformation relationship acquisition unit 702, a correction unit 703, and a rotation center acquisition unit 704.

[0147] The real-time coordinate acquisition unit 701 is used to acquire the real-time position coordinates of the pelvic target point and the femoral head target point.

[0148] The position transformation relationship acquisition unit 702 calculates the position transformation relationship between the pelvic target point and the femoral head target point based on the real-time position coordinates of the pelvic target point when the acquisition frequencies of the pelvic target point and the femoral head target point are consistent.

[0149] The correction unit 703 is used to determine the corrected second position coordinates of the femoral head target point at the current time based on the first position coordinates of the femoral head target point in the real-time position coordinates at the current time and the position transformation relationship;

[0150] The rotation center acquisition unit 704 is used to calculate the rotation center of the femoral head at the current moment based on the second position coordinates of the femoral head target point.

[0151] In some embodiments, the femoral head center real-time calculation device further includes: a first time information acquisition unit, a second time information acquisition unit, a coordinate synchronization unit, and a real-time position coordinate update unit.

[0152] The first-time information acquisition unit is used to acquire the real-time position coordinates of the femoral head target point and the corresponding first-time information in the first-time coordinate system.

[0153] The second time information acquisition unit is used to acquire the second time information corresponding to the pelvic target point in the second time coordinate system based on the first time information.

[0154] The coordinate synchronization unit is used to determine the real-time position coordinates of the pelvic target point and the femoral head target point under the first time information based on the first time information, the second time information, and the position coordinates of the pelvic target point under the second time information.

[0155] The real-time position coordinate update unit is used to update the real-time position coordinates of the pelvic target point and the femoral head target point under the first time information to the real-time position coordinates of the pelvic target point.

[0156] In some embodiments, the second time information includes two time points adjacent to the first time information in a second time coordinate system.

[0157] In some embodiments, the position transformation relationship acquisition unit 702 includes: a centroid calculation module, a parameter acquisition module, and a calculation module.

[0158] The centroid calculation module is used to calculate the centroid of the pelvic tracking target point at the preset time and the current time, respectively; the tracking target point includes at least three non-collinear target points of the pelvis.

[0159] The parameter acquisition module is used to determine the rotation matrix and translation amount of the tracking target point based on the centroid of the tracking target point at the current time and the position coordinates of each tracking target point at the preset time and the current time.

[0160] The calculation module is used to determine the positional transformation relationship of the pelvic target point between the current time and the preset time based on the rotation matrix, translation amount, and position coordinates of the tracking target point at the current time and the preset time.

[0161] In some embodiments, the rotation center acquisition unit 704 includes: a femoral head target point acquisition module, a first sample point set acquisition module, and a first rotation center calculation module.

[0162] The femoral head target point acquisition module is used to select at least four femoral head target points within a time period determined by the current time and the initial time.

[0163] The first sample point set acquisition module is used to determine the sample point set based on the second position coordinates of at least four femoral head target points;

[0164] The first rotation center calculation module is used to calculate the rotation center of the femoral head at the current moment based on the set of sample points.

[0165] In some embodiments, the rotation center acquisition unit 704 includes: a second sample point set acquisition module, a potential rotation center calculation module, a first outlier removal module, and a second rotation center calculation module.

[0166] The second sample point set acquisition module is used to determine the sample point set based on the second position coordinates of at least four non-coplanar femoral head target points.

[0167] The potential rotation center calculation module is used to calculate multiple potential rotation centers of the femoral center at the current moment based on multiple sets of sample points.

[0168] The first outlier removal module is used to determine a first type of inlier among the multiple potential rotation centers based on the position coordinates corresponding to the multiple potential rotation centers and a preset outlier metric threshold.

[0169] The second rotation center calculation module is used to determine the rotation center of the femoral center at the current moment based on multiple potential rotation centers after the first removal of abnormal points.

[0170] In some embodiments, the second rotation center calculation module includes: a mean coordinate acquisition module, a second outlier removal module, and a rotation center determination module.

[0171] The mean coordinate acquisition module is used to calculate the mean coordinates of multiple points within the first class when the number of points within the first class is greater than a preset threshold for the number of points within the first class.

[0172] The second outlier removal module is used to determine a second type of inlier among multiple potential rotation centers based on the position coordinates corresponding to the potential rotation centers, the mean coordinates, and the outlier metric threshold.

[0173] The first rotation center determination submodule is used to determine the mean coordinates of all intra-class points as the rotation center of the femur at the current moment when the number of intra-class points is equal to the preset threshold for the number of intra-class points.

[0174] In some embodiments, the second rotation center calculation module further includes: an in-class point update module, an iteration module, and a second rotation center determination submodule.

[0175] The in-class point update module is used to update the in-class point count threshold to the current in-class point count when the number of in-class points in the second class is greater than the preset threshold for the number of in-class points in the second class.

[0176] The iteration module is used to repeatedly iterate the steps for determining the first and second class interior points until the preset number of iterations is reached.

[0177] The second rotation center determination submodule is used to determine the mean coordinates of all intraclass points corresponding to the preset number of iterations as the rotation center of the femoral center at the current moment.

[0178] It should be noted that the above modules can be functional modules or program modules, and can be implemented through software or hardware. For modules implemented through hardware, the above modules can reside in the same processor; or the above modules can be located in different processors in any combination.

[0179] In addition, combined Figure 1 The real-time calculation method for the femoral head center described in this application embodiment can be implemented by a surgical robot. Figure 8 This is a schematic diagram of the hardware structure of a surgical robot according to an embodiment of this application.

[0180] The surgical robot may include a processor 81 and a memory 82 storing computer program instructions.

[0181] Specifically, the processor 81 may include a central processing unit (CPU), an application specific integrated circuit (ASIC), or one or more integrated circuits that can be configured to implement the embodiments of this application.

[0182] The memory 82 may include a mass storage device for data or instructions. For example, and not limitingly, the memory 82 may include a hard disk drive (HDD), a floppy disk drive, a solid-state drive (SSD), flash memory, an optical disk drive, a magneto-optical disk drive, magnetic tape, or a Universal Serial Bus (USB) drive, or a combination of two or more of these. Where appropriate, the memory 82 may include removable or non-removable (or fixed) media. Where appropriate, the memory 82 may be internal or external to a data processing device. In a particular embodiment, the memory 82 is non-volatile memory. In a particular embodiment, the memory 82 includes read-only memory (ROM) and random access memory (RAM). Where appropriate, the ROM may be a mask-programmed ROM, a programmable read-only memory (PROM), an erasable read-only ROM (EPROM), an electrically erasable read-only ROM (EEPROM), an electrically alterable read-only ROM (EAROM), or flash memory, or a combination of two or more of these. Where appropriate, the RAM can be Static Random-Access Memory (SRAM) or Dynamic Random-Access Memory (DRAM). DRAM can be Fast Page Mode Dynamic Random-Access Memory (FPMDRAM), Extended Data Out Dynamic Random-Access Memory (EDODRAM), Synchronous Dynamic Random-Access Memory (SDRAM), etc.

[0183] The memory 82 can be used to store or cache various data files that need to be processed and / or communicated, as well as possible computer program instructions executed by the processor 81.

[0184] The processor 81 reads and executes computer program instructions stored in the memory 82 to implement any of the real-time calculation methods for the femoral head center in the above embodiments.

[0185] In some embodiments, the surgical robot may further include a memory 83 and a bus 80. For example, Figure 8 As shown, processor 81, memory 82, and memory 83 are connected via bus 80 and communicate with each other.

[0186] The memory 83 is used to enable communication between the various modules, devices, units, and / or equipment in the embodiments of this application. The memory 83 can also enable data communication with other components such as external devices, image / data acquisition devices, databases, external storage, and image / data processing workstations.

[0187] Bus 80 includes hardware, software, or both, that couples the components of the surgical robot together. Bus 80 includes, but is not limited to, at least one of the following: Data Bus, Address Bus, Control Bus, Expansion Bus, and Local Bus. For example, and not as a limitation, bus 80 may include an Accelerated Graphics Port (AGP) or other graphics bus, an Extended Industry Standard Architecture (EISA) bus, a Front Side Bus (FSB), a HyperTransport (HT) interconnect, an Industry Standard Architecture (ISA) bus, an InfiniBand interconnect, a Low Pin Count (LPC) bus, a memory bus, a Micro Channel Architecture (MCA) bus, a Peripheral Component Interconnect (PCI) bus, a PCI-Express (PCI-X) bus, a Serial Advanced Technology Attachment (SATA) bus, a Video Electronics Standards Association Local Bus (VLB) bus, or other suitable buses, or a combination of two or more of these. Where appropriate, bus 80 may include one or more buses. Although specific buses are described and illustrated in the embodiments of this application, this application considers any suitable bus or interconnection.

[0188] For example, the surgical robot includes a robotic arm and an optical navigation instrument connected to the robotic arm. The optical navigation system allows for surgical planning of the robotic arm's movement trajectory, enabling the operator to interactively control the robotic arm's force. Based on acquired program instructions, the optical navigation system can execute the real-time femoral head center calculation method described in this embodiment, thereby realizing the aforementioned real-time femoral head center calculation method. Optionally, the surgical robot also includes a surgical trolley for supporting the robotic arm, ensuring its stability during movement and use.

[0189] Furthermore, in conjunction with the real-time calculation method for the femoral head center in the above embodiments, this application embodiment can provide a computer-readable storage medium for implementation. This computer-readable storage medium stores computer program instructions; when executed by a processor, these computer program instructions implement any of the real-time calculation methods for the femoral head center in the above embodiments.

[0190] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0191] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.

Claims

1. A method for real-time calculation of the center of a femoral head, characterized by, The method comprises the following steps: acquiring real-time position coordinates of a pelvic target point and a femoral head target point; the pelvic target point is a target point that needs to be tracked in a pelvic part of a surgical target, and the femoral head target point is a target point that needs to be tracked in a femoral part of the surgical target; calculating a position transformation relationship of the pelvic target point between a preset time and a current time according to the real-time position coordinates of the pelvic target point; determining a second position coordinate of the femoral head target point at the current time by correcting a first position coordinate of the femoral head target point at the current time according to the position transformation relationship; calculating a rotation center of the femoral head at the current time according to the second position coordinate of the femoral head target point; when the acquisition frequencies of the pelvic target point and the femoral head target point are inconsistent, after the step of acquiring the real-time position coordinates of the pelvic target point and the femoral head target point, the method further comprises a coordinate synchronization step: acquiring first time information corresponding to the real-time position coordinates of the femoral head target point in a first time coordinate system; acquiring second time information corresponding to the pelvic target point in a second time coordinate system according to the first time information; determining real-time position coordinates of the pelvic target point corresponding to the femoral head target point in the first time information according to the first time information, the second time information and the position coordinates of the pelvic target point in the second time information; and updating the real-time position coordinates of the pelvic target point corresponding to the femoral head target point in the first time information as the real-time position coordinates of the pelvic target point.

2. The femoral head center real-time calculation method of claim 1, wherein, The step of calculating the position transformation relationship of the pelvic target point between the preset time and the current time according to the real-time position coordinates of the pelvic target point comprises the following steps: calculating the center of mass of the pelvic tracking target point at the preset time and the current time, respectively; determining a shift matrix of the tracking target point according to the center of mass of the tracking target point at the current time, and the position coordinates of each tracking target point at the preset time and the current time; determining the position transformation relationship of the pelvic target point between the preset time and the current time according to the shift matrix of the tracking target point and the position coordinates of the tracking target point at the current time and the preset time.

3. The femoral head center real-time calculation method of claim 1, wherein, The step of calculating the rotation center of the femoral head at the current time according to the second position coordinate of the femoral head target point comprises the following steps: selecting at least four femoral head target points in a time period determined by the current time and an initial time; determining a sample point set according to the second position coordinates of the at least four femoral head target points; calculating the rotation center of the femoral head at the current time according to the sample point set.

4. The femoral head center real-time calculation method of claim 1, wherein, The step of calculating the rotation center of the femoral head at the current time according to the second position coordinate of the femoral head target point comprises the following steps: determining a plurality of sample point sets according to the second position coordinates of the at least four femoral head target points that are not coplanar; calculating a plurality of potential rotation centers corresponding to the femoral center at the current time according to the plurality of sample point sets; determining a first inlier in the plurality of potential rotation centers according to position coordinates corresponding to the plurality of potential rotation centers and a preset outlying degree threshold. According to the first type of inlier, a rotation center of the femoral head center at the current time is determined.

5. The femoral head center real-time calculation method of claim 4, wherein, According to the first type of inlier, a rotation center of the femoral head center at the current time is determined, comprising: When the number of the first type of inliers is greater than a preset first type of inlier number threshold, a mean coordinate of a plurality of the first type of inliers is calculated; According to the position coordinate corresponding to the potential rotation center, the mean coordinate and the outlying measure threshold, a second type of inlier is determined from among a plurality of the potential rotation centers; When the number of the second type of inliers is equal to a preset second type of inlier number threshold, a mean coordinate of all the second type of inliers is determined as the rotation center of the femoral head center at the current time.

6. The femoral head center real-time calculation method of claim 4, wherein, Further comprising: A standard deviation and a residual are calculated based on the rotation centers at a plurality of times; The standard deviation and the residual are compared with a preset standard deviation threshold and a residual threshold, respectively, to determine whether the data acquisition is sufficient according to the comparison result.

7. A femoral head center real-time computing device, comprising: Comprise: A real-time coordinate acquisition unit is configured to acquire real-time position coordinates of a pelvic target point and a femoral head target point; the pelvic target point is a target point that needs to be tracked in a target pelvic part of a surgery, and the femoral head target point is a target point that needs to be tracked in a target femoral part of a surgery; A position transformation relationship acquisition unit is configured to, when the acquisition frequencies of the pelvic target point and the femoral head target point are consistent, calculate a position transformation relationship of the pelvic bone between a current time and a preset time according to the real-time position coordinates of the pelvic target point; A correction unit is configured to determine a second position coordinate of the femoral head target point at the current time after correction according to a first position coordinate of the real-time position coordinates of the femoral head target point at the current time and the position transformation relationship; A rotation center calculation unit is configured to calculate a rotation center of the femoral head at the current time according to the second position coordinate of the femoral head target point; When the acquisition frequencies of the pelvic target point and the femoral head target point are inconsistent, after the real-time position coordinates of the pelvic target point and the femoral head target point are acquired, a coordinate synchronization step is further included: acquiring first time information corresponding to the real-time position coordinates of the femoral head target point in a first time coordinate system; acquiring second time information corresponding to the pelvic target point in a second time coordinate system according to the first time information; determining real-time position coordinates of the pelvic target point corresponding to the femoral head target point in the first time information according to the first time information, the second time information and the position coordinates of the pelvic target point in the second time information; and updating the real-time position coordinates of the pelvic target point corresponding to the femoral head target point in the first time information as the real-time position coordinates of the pelvic target point.

8. A surgical robot comprising a memory and a processor, characterised in that, The memory stores a computer program, and the processor is configured to run the computer program to execute the femoral head center real-time calculation method in any one of claims 1 to 6.

9. A computer readable storage medium having stored thereon a computer program, characterized in that, The computer program is executed by the processor to implement the femoral head center real-time calculation method in any one of claims 1 to 6.

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