CN115272525B - Spline curve generation method, device, equipment and storage medium - Google Patents
Spline curve generation method, device, equipment and storage medium Download PDFInfo
- Publication number
- CN115272525B CN115272525B CN202211188451.3A CN202211188451A CN115272525B CN 115272525 B CN115272525 B CN 115272525B CN 202211188451 A CN202211188451 A CN 202211188451A CN 115272525 B CN115272525 B CN 115272525B
- Authority
- CN
- China
- Prior art keywords
- spline curve
- universal head
- curve
- spline
- head screw
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Images
Classifications
-
- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06T—IMAGE DATA PROCESSING OR GENERATION, IN GENERAL
- G06T11/00—2D [Two Dimensional] image generation
- G06T11/20—Drawing from basic elements, e.g. lines or circles
- G06T11/203—Drawing of straight lines or curves
Landscapes
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Engineering & Computer Science (AREA)
- Theoretical Computer Science (AREA)
- Image Generation (AREA)
Abstract
The invention relates to the field of artificial intelligence, and discloses a spline curve generation method, a spline curve generation device, spline curve generation equipment and a storage medium, which are used for improving the smoothness of a spline curve of a vertebral body nail. The spline curve generation method includes: acquiring nail placing scheme data of a target vertebral body, analyzing the nail placing scheme data to obtain a plurality of universal head screw parameter attributes and a plurality of universal head screw position data; acquiring nail rod parameter data, and calculating curve parameters of each universal head screw according to the nail rod parameter data, the parameter attributes of the universal head screws and the position data of the universal head screws; spline curve fitting is carried out on curve parameters of each universal head screw according to the position data of the universal head screws to obtain an initial spline curve, and the curvature change rate of the initial spline curve is calculated; and calling a preset optimization model to calculate the optimal solution of the initial spline curve according to the curvature change rate, and generating a target spline curve.
Description
Technical Field
The invention relates to the field of artificial intelligence, in particular to a spline curve generation method, a spline curve generation device, spline curve generation equipment and a storage medium.
Background
In the operation of internal fixation of the vertebral body, after the nail placing scheme is determined, the nail rod on each screw nail cap passes through the initial point and the ending point to be connected end to end, and a spline curve is fitted.
Because the existing scheme does not relate to the degree of freedom of a screw cap, the starting point and the ending point of the nail rod pass through the nail cap and completely depend on the position and the angle of a screw rod in the nail placing scheme, and the position arrangement of the nail cap in the whole system is not considered, so that the smoothness of a fitted spline curve is poor, the curve is twisted and sunk, and the requirement of a bent rod in practical application is not met.
Disclosure of Invention
The invention provides a spline curve generation method, a spline curve generation device, spline curve generation equipment and a storage medium, which are used for improving the smoothness of a spline curve of a vertebral body nailing device.
The first aspect of the present invention provides a spline curve generation method, including: acquiring nail placing scheme data of a target vertebral body, and analyzing the nail placing scheme data to obtain a plurality of universal head screw parameter attributes and a plurality of universal head screw position data; acquiring nail rod parameter data, and calculating curve parameters of each universal head screw according to the nail rod parameter data, the parameter attributes of the universal head screws and the position data of the universal head screws; performing spline curve fitting on the curve parameters of each universal head screw according to the position data of the universal head screws to obtain an initial spline curve, and calculating the curvature change rate of the initial spline curve; and calling a preset optimization model to calculate the optimal solution of the initial spline curve according to the curvature change rate, and generating a target spline curve.
Optionally, in a first implementation manner of the first aspect of the present invention, the obtaining the nail rod parameter data, and calculating a curve parameter of each of the universal head screws according to the nail rod parameter data, the multiple universal head screw parameter attributes, and the multiple universal head screw position data includes: acquiring nail rod parameter data, wherein the nail rod parameter data comprises: the radius of the nail rod; respectively extracting the universal head rotation spherical center coordinates in the position data of each universal head screw; respectively extracting the thickness of the bottom end of the nut in the parameter attribute of each universal head screw; calculating a target distance according to the thickness of the bottom end of the screw cap, the radius of the nail rod and the distance from a preset sphere center to the bottom end of the screw cap; generating a target point coordinate according to the target distance and the universal head rotating spherical center coordinate; and generating curve parameters of each universal head screw according to the coordinates of the target point.
Optionally, in a second implementation manner of the first aspect of the present invention, the generating a curve parameter of each universal head screw according to the target point coordinates includes: acquiring a curve starting point and a curve ending point corresponding to a screw cap of each universal head screw; generating coordinate information corresponding to the curve starting point and the curve ending point based on the target point coordinates to obtain starting point coordinate information and ending point coordinate information; and taking the coordinate information of the starting point, the coordinate information of the ending point and the coordinate information of the target point as the curve parameters of each universal head screw.
Optionally, in a third implementation manner of the first aspect of the present invention, the performing spline curve fitting on a curve parameter of each universal head screw according to the position data of the plurality of universal head screws to obtain an initial spline curve, and calculating a curvature change rate of the initial spline curve includes: sequentially arranging the universal head screws according to the position data of the universal head screws to obtain an arrangement result; spline curve fitting is carried out on the curve parameters of each universal head screw according to the arrangement result to obtain an initial spline curve; and segmenting the initial spline curve to obtain a plurality of segmental spline curves, and carrying out curvature change calculation on the segmental spline curves to obtain the curvature change rate.
Optionally, in a fourth implementation manner of the first aspect of the present invention, the segmenting the initial spline curve to obtain a plurality of segmental spline curves, and performing curvature change calculation on the plurality of segmental spline curves to obtain a curvature change rate of the initial spline curve includes: segmenting the initial spline curve by adopting a preset interpolation method to obtain a plurality of segment spline curves; respectively carrying out curvature change calculation on each segment of spline curve to obtain the curvature change rate of each segment of spline curve; and adding the curvature change rate of each segment of spline curve to obtain the curvature change rate of the initial spline curve.
Optionally, in a fifth implementation manner of the first aspect of the present invention, the separately performing curvature change calculation on each segmental spline curve to obtain a curvature change rate of each segmental spline curve includes: acquiring the arc length of each segment of spline curve; calculating the curvature of each segment spline curve according to the arc length; and carrying out curvature change calculation on each segment of spline curve according to the curvature of each segment of spline curve to obtain the curvature change rate of each segment of spline curve.
Optionally, in a sixth implementation manner of the first aspect of the present invention, the invoking a preset optimization model to calculate an optimal solution of the initial spline according to the curvature change rate to generate a target spline, where the method includes: calling a preset optimization model to perform segmental search on the initial spline curve to obtain the best point of each segment; and performing optimal solution calculation on the initial spline curve according to the curvature change rate so as to minimize the curvature change rate of the initial spline curve and generate a target spline curve.
A second aspect of the present invention provides a spline curve generation apparatus including: the acquisition module is used for acquiring the nail placing scheme data of the target vertebral body and analyzing the nail placing scheme data to obtain a plurality of universal head screw parameter attributes and a plurality of universal head screw position data; the calculation module is used for acquiring nail rod parameter data and calculating curve parameters of each universal head screw according to the nail rod parameter data, the parameter attributes of the universal head screws and the position data of the universal head screws; the fitting module is used for carrying out spline curve fitting on curve parameters of each universal head screw according to the position data of the universal head screws to obtain an initial spline curve and calculating the curvature change rate of the initial spline curve; and the generating module is used for calling a preset optimization model to calculate the optimal solution of the initial spline curve according to the curvature change rate so as to generate a target spline curve.
Optionally, in a first implementation manner of the second aspect of the present invention, the calculation module further includes: the processing unit is used for acquiring the nail rod parameter data, wherein the nail rod parameter data comprises: the radius of the nail rod; respectively extracting the universal head rotation spherical center coordinates in the position data of each universal head screw; respectively extracting the thickness of the bottom end of the nut in the parameter attribute of each universal head screw; calculating a target distance according to the thickness of the bottom end of the screw cap, the radius of the nail rod and the distance from a preset sphere center to the bottom end of the screw cap; generating a target point coordinate according to the target distance and the universal head rotating spherical center coordinate; and the generating unit is used for generating curve parameters of each universal head screw according to the target point coordinates.
Optionally, in a second implementation manner of the second aspect of the present invention, the generating unit is specifically configured to: acquiring a curve starting point and a curve ending point corresponding to a screw cap of each universal head screw; generating coordinate information corresponding to the curve starting point and the curve ending point based on the target point coordinates to obtain starting point coordinate information and ending point coordinate information; and taking the coordinate information of the starting point, the coordinate information of the ending point and the coordinate information of the target point as the curve parameters of each universal head screw.
Optionally, in a third implementation manner of the second aspect of the present invention, the fitting module further includes: the arrangement unit is used for sequentially arranging the universal head screws according to the position data of the universal head screws to obtain an arrangement result; the fitting unit is used for performing spline curve fitting on the curve parameters of each universal head screw according to the arrangement result to obtain an initial spline curve; and the calculation unit is used for segmenting the initial spline curve to obtain a plurality of segmental spline curves and carrying out curvature change calculation on the segmental spline curves to obtain the curvature change rate.
Optionally, in a fourth implementation manner of the second aspect of the present invention, the calculating unit further includes: a segmentation subunit, configured to segment the initial spline curve by using a preset interpolation method to obtain multiple segment spline curves; the calculating subunit is used for respectively calculating the curvature change of each segment of spline curve to obtain the curvature change rate of each segment of spline curve; and the addition subunit is used for adding the curvature change rate of each segment of spline curve to obtain the curvature change rate of the initial spline curve.
Optionally, in a fifth implementation manner of the second aspect of the present invention, the calculating subunit is specifically configured to: acquiring the arc length of each segment of spline curve; calculating the curvature of each segment spline curve according to the arc length; and carrying out curvature change calculation on each segment of spline curve according to the curvature of each segment of spline curve to obtain the curvature change rate of each segment of spline curve.
Optionally, in a sixth implementation manner of the second aspect of the present invention, the generating module is specifically configured to: calling a preset optimization model to perform segmental search on the initial spline curve to obtain the best point of each segment; and performing optimal solution calculation on the initial spline curve according to the curvature change rate so as to minimize the curvature change rate of the initial spline curve and generate a target spline curve.
A third aspect of the present invention provides a spline curve generation apparatus including: a memory and at least one processor, the memory having instructions stored therein; the at least one processor invokes the instructions in the memory to cause the spline curve generation device to perform the spline curve generation method described above.
A fourth aspect of the present invention provides a computer-readable storage medium having stored therein instructions, which, when run on a computer, cause the computer to execute the spline curve generation method described above.
According to the technical scheme, nail rod parameter data are obtained, and curve parameters of all universal head screws are calculated according to the nail rod parameter data, the parameter attributes of the universal head screws and the position data of the universal head screws, wherein an optimization model is established by adopting a spherical coordinate system, the number of unknown variables is reduced, constraint conditions are simplified, the optimization problem is easier to solve, the curvature change rate is used as a spline curve smoothness evaluation index, the sum of all sections of spline curves is used as a target function, the aim of increasing the overall smoothness of the curve is fulfilled, the optimization model is adopted and is an effective direct search method, the complex target function can be still solved efficiently, and the optimal universal head placement angle can be obtained. The optimized target spline curve is smoother, less in twisting and hollow and more suitable for nail rods in practical application.
Drawings
FIG. 1 is a schematic diagram of an embodiment of a spline curve generation method in an embodiment of the present invention;
FIG. 2 is a schematic diagram of another embodiment of a spline curve generation method in the embodiment of the present invention;
FIG. 3 is a schematic diagram of an embodiment of a spline curve generation apparatus in an embodiment of the present invention;
FIG. 4 is a schematic diagram of another embodiment of a spline curve generation apparatus in an embodiment of the present invention;
FIG. 5 is a schematic diagram of one embodiment of a spline curve generation apparatus in an embodiment of the present invention;
FIG. 6 is a schematic diagram of coordinates of a target point in a three-dimensional orthogonal coordinate system according to an embodiment of the present invention;
FIG. 7 is a schematic diagram of coordinates of a target point in a universal head screw according to an embodiment of the present invention;
FIG. 8 is a parameter diagram of a universal head screw according to an embodiment of the present invention;
FIG. 9 is a graph illustrating curve parameters according to an embodiment of the present invention;
FIG. 10 is a graph illustrating the rate of change of curvature in an embodiment of the present invention;
FIG. 11 is a schematic diagram of a target spline curve in an embodiment of the present invention.
Detailed Description
The embodiment of the invention provides a spline curve generation method, a spline curve generation device, spline curve generation equipment and a storage medium, which are used for improving the smoothness of a spline curve of a vertebral body nail. The terms "first," "second," "third," "fourth," and the like in the description and in the claims, as well as in the drawings, if any, are used for distinguishing between similar elements and not necessarily for describing a particular sequential or chronological order. It will be appreciated that the data so used may be interchanged under appropriate circumstances such that the embodiments described herein may be implemented in other sequences than those illustrated or described herein. Furthermore, the terms "comprises," "comprising," or "having," and any variations thereof, are intended to cover non-exclusive inclusions, such that a process, method, system, article, or apparatus that comprises a list of steps or elements is not necessarily limited to those steps or elements expressly listed, but may include other steps or elements not expressly listed or inherent to such process, method, article, or apparatus.
For convenience of understanding, a specific flow of an embodiment of the present invention is described below, and referring to fig. 1, an embodiment of a spline curve generation method in an embodiment of the present invention includes:
101. acquiring nail placing scheme data of a target vertebral body, analyzing the nail placing scheme data to obtain a plurality of universal head screw parameter attributes and a plurality of universal head screw position data;
it is to be understood that the execution subject of the present invention may be a spline curve generation apparatus, and may also be a terminal or a server, which is not limited herein. The embodiment of the present invention is described by taking a server as an execution subject.
It should be noted that, when a spline curve is generated, the start point and the end point of a nail rod pass through a nail cap and completely depend on the position and the angle of a screw rod in a nail placing scheme, and the position arrangement of the nail cap in the whole system is not considered, so that the smoothness of the fitted spline curve is poor, the curve is twisted and sunk, and the requirements of the nail rod in practical application are not met.
102. Acquiring nail rod parameter data, and calculating a curve parameter of each universal head screw according to the nail rod parameter data, the parameter attributes of the universal head screws and the position data of the universal head screws;
it should be noted that, in the conventional nail placement scheme, each screw parameter attribute and position data in a physical coordinate system of a series of universal head screws disposed on a target vertebral body are shown in fig. 8, where fig. 8 is a schematic diagram of parameters in a universal head screw according to an embodiment of the present invention, where the parameter attribute includes a screw diameter, a screw length, and position information includes a screw tip coordinate and a universal head rotation spherical center coordinate. For each screw, the position of the screw rod is fixed, the position of the screw cap can freely rotate around the sphere center, and the maximum angle between the limit position and the direction of the screw rod is 15 degrees. The nail rod needs to penetrate through all the screw nuts and be attached to the screw nuts, specifically, the server calculates curve parameters of all the universal head screws according to the nail rod parameter data, the parameter attributes of the universal head screws and the position data of the universal head screws, and then obtains a spline curve penetrating through the center point of the nail rod, so that the smoothness of the spline curve is the highest.
103. Spline curve fitting is carried out on curve parameters of each universal head screw according to the position data of the universal head screws to obtain an initial spline curve, and the curvature change rate of the initial spline curve is calculated;
it should be noted that, in the nail placing scheme, the nail rod will be attached to the nail cap, so the spline curve needs to be a straight line through each internal stage of the nail cap, as shown in fig. 9, E1 and E2 are two points at the beginning and end of the spline curve passing through the nail cap at the center of the nail rod, the curve is a straight line between E1 and E2, and the point P shown in the 2,3 is the midpoint of E1 and E2. If the coordinates of point P are known, E1, E2 are two points perpendicular to the plane of vector V _ PS and at a fixed distance from P, and can be uniquely determined by the rotation angle β. To sum up, for each screw in the screw system, the coordinates of the starting and ending points E1, E2 of the spline curve passing through the nut can be calculated in the physical three-dimensional orthogonal coordinate system by the unknown variables ɸ, θ, β. The coordinates of E1 and E2 are used as main parameters for expressing the smoothness of the spline curve in an objective function. The method comprises the following steps that ɸ is E1, a midpoint P of E2 is a polar angle in a nut spherical coordinate system, theta is E1, a midpoint P of E2 is an azimuth angle in the nut spherical coordinate system, beta is an E1E 2 vector rotation angle, and then a server performs spline curve fitting on curve parameters of all universal head screws according to position data of the universal head screws to obtain an initial spline curve and calculate the curvature change rate of the initial spline curve.
104. And calling a preset optimization model to calculate the optimal solution of the initial spline curve according to the curvature change rate, and generating a target spline curve.
Specifically, the final server needs to maximize the smoothness of the spline curve according to the Curvature change rate, and describes the smoothness of the spline curve by using the index variance of Curvature (Curvature change rate, hereinafter referred to as Curvature change rate).
In the embodiment of the invention, the nail rod parameter data are obtained, and the curve parameter of each universal head screw is calculated according to the nail rod parameter data, the parameter attributes of a plurality of universal head screws and the position data of the plurality of universal head screws, wherein an optimization model is established by adopting a spherical coordinate system, the number of unknown variables is reduced, the constraint condition is simplified, the optimization problem is easier to solve, the curvature change rate is used as a spline curve smoothness evaluation index, the sum of all sections of spline curves is used as a target function, the aim of increasing the overall smoothness of the curve is fulfilled, the optimization model is an effective direct search method, the complex target function can still be efficiently solved, and the optimal universal head placing angle can be determined. The optimized target spline curve is smoother, less in twisting and hollow and more suitable for nail rods in practical application.
Referring to fig. 2, another embodiment of the spline curve generation method according to the embodiment of the present invention includes:
201. acquiring screw placing scheme data of a target vertebral body, and analyzing the screw placing scheme data to obtain a plurality of universal head screw parameter attributes and a plurality of universal head screw position data;
specifically, in this embodiment, the specific implementation of step 201 is similar to that of step 101, and is not described herein again.
202. Acquiring nail rod parameter data, and calculating curve parameters of each universal head screw according to the nail rod parameter data, the parameter attributes of the universal head screws and the position data of the universal head screws;
specifically, acquire nail stick parameter data, wherein, nail stick parameter data includes: the radius of the nail rod; respectively extracting a universal head rotation spherical center coordinate in position data of each universal head screw, as shown in fig. 7, fig. 7 is a schematic coordinate diagram of a target point coordinate in the universal head screw in the embodiment of the invention, and respectively extracting a nut bottom end thickness in parameter attributes of each universal head screw; calculating a target distance according to the thickness of the bottom end of the nut, the radius of the nail rod and the distance from the preset spherical center to the bottom end of the nut; generating a target point coordinate according to the target distance and the universal head rotating spherical center coordinate; and generating curve parameters of each universal head screw according to the coordinates of the target point.
In the known nail placing scheme, each screw parameter attribute of a series of universal head screws arranged on a target vertebral body and position data under a physical coordinate system are arranged, wherein the parameter attributes comprise screw diameter and screw length, and the position information comprises screw tip coordinates and universal head rotation spherical center coordinates. For each screw, the position of the screw rod is fixed, the position of the screw cap can freely rotate around the sphere center, and the maximum angle between the limit position and the direction of the screw rod is 15 degrees. The nail rod needs to penetrate through all the screw nuts in the universal head screw and be attached to the screw nuts. This technical patent is anticipated is surveing the spline curve that passes nail stick central point for its smoothness is the highest, and it is required to explain that, in this application embodiment, the server should simplify the constraint condition as far as possible in order to make the optimization problem more solve, avoids involving complicated calculation. Since the constraint condition of the problem is mainly the angle limitation, the variable model adopts a spherical coordinate system. As shown in fig. 6, the spherical coordinate system will represent the coordinates of the point P in the three-dimensional orthogonal coordinate system by the spherical coordinates (r, ɸ, θ). Where r is the radial distance, ɸ is the polar angle, and θ is the azimuthal angle.
Specifically, a curve starting point and a curve ending point corresponding to a screw cap of each universal head screw are obtained; generating coordinate information corresponding to the curve starting point and the curve ending point based on the coordinates of the target point to obtain the coordinate information of the starting point and the coordinate information of the ending point; and taking the coordinate information of the starting point, the coordinate information of the ending point and the coordinate information of the target point as the curve parameters of each universal head screw.
The method comprises the steps of obtaining a horizontal coordinate and a vertical coordinate of a starting point of a curve, selecting a point to be calculated in the curve, calculating an arc length between the point and the starting point, respectively constructing a cosine function and a sine function related to the arc length, respectively integrating the cosine function and the sine function between 0 and l to obtain a cosine integral value and a sine integral value, and adding the cosine integral value and the horizontal coordinate value of the starting point to obtain the horizontal coordinate of the point to be calculated; adding the sine integral value and the vertical coordinate value of the starting point to obtain the vertical coordinate of the point to be calculated, and generating coordinate information corresponding to the starting point and the ending point of the curve based on the coordinates of the target point to obtain the coordinate information of the starting point and the coordinate information of the ending point; the starting point coordinate information, the ending point coordinate information and the target point coordinate information are used as curve parameters of each universal head screw.
203. Sequentially arranging the universal head screws according to the position data of the universal head screws to obtain an arrangement result;
204. spline curve fitting is carried out on the curve parameters of each universal head screw according to the arrangement result to obtain an initial spline curve;
205. segmenting the initial spline curve to obtain a plurality of segment spline curves, and carrying out curvature change calculation on the plurality of segment spline curves to obtain a curvature change rate;
specifically, a preset interpolation method is adopted to segment the initial spline curve to obtain a plurality of segment spline curves; respectively carrying out curvature change calculation on each segment of spline curve to obtain the curvature change rate of each segment of spline curve; and adding the curvature change rate of each segment of spline curve to obtain the curvature change rate of the initial spline curve.
The server sequentially arranges the universal head screws according to the position data of the universal head screws to obtain an arrangement result, spline curve fitting is carried out on curve parameters of each universal head screw according to the arrangement result to obtain an initial spline curve, the initial spline curve is segmented to obtain a plurality of segment spline curves, curvature change calculation is carried out on the segment spline curves to obtain curvature change rate, and specifically, the defects aim at maximizing the smoothness of the spline curves. The patent describes the smoothness of a spline curve by adopting the index curvature change rate. As shown in the following equation, K is the curvature, s is the arc length, and the rate of change of curvature is the integral of the square of the derivative of K with s over s. As can be seen from the diagram 10, the less the spline curve twists or potholes, i.e., is smoother, the smaller the curvature change rate value, wherein the formula is as follows:
to make the above integral easier to solve, taking the spline curve equation as C (t), the above equation can be converted into an integral over the curve parameter t, as shown below:
wherein the curvature can be expressed as:
the curvature change rate value corresponding to the curve can be obtained by establishing spline curve parameters through calculation.
Specifically, the arc length of each segment of spline curve is obtained; calculating the curvature of the spline curve of each segment according to the arc length; and calculating the curvature change of each section of spline curve according to the curvature of each section of spline curve to obtain the curvature change rate of each section of spline curve.
Specifically, the server is arranged in sequence by screws in the universal head screw, for any screw n, the coordinates of E1 and E2 can be obtained by an unknown variable group (ɸ, theta, beta) n, and then the starting point E1 of the screw n and the end point E2 of the previous screw n-1 can be calculated. Given two-point coordinates and a first derivative, a cubic spline curve can be established through an Hermit interpolation method, so that the curvature change rate can be obtained through the parameters of the spline curve, and then the curvature change rate of the spline curve can be obtained through integration. The curvature change rate values of all the segment splines in the set are added to obtain the objective function for minimizing the optimization problem.
206. And calling a preset optimization model to calculate the optimal solution of the initial spline curve according to the curvature change rate, and generating a target spline curve.
Specifically, a preset optimization model is called to conduct segmental search on the initial spline curve to obtain the best point of each segment; and performing optimal solution calculation on the initial spline curve according to the curvature change rate so as to minimize the curvature change rate of the initial spline curve and generate a target spline curve.
The optimization problem can be summarized as that for the screws arranged in the universal head screw, respectively using (ɸ, theta, beta) as unknown variables, so as to obtain the coordinates of a starting point and an end point E1, E2, connecting the starting point and the end point by two screw caps, fitting a spline curve, obtaining the curvature change rate, and obtaining the sum of all sections of curvature change rates, namely the objective function of minimization, namely obtaining the minimum overall curvature change of the step-type spline curve, wherein the whole body is smooth, and the optimization problem adopts Powell algorithm, so that the optimization problem is an effective direct search method, and the method is essentially a conjugate direction method. The optimization algorithm is used because the algorithm does not require that the objective function be derivable and can perform efficient searching with constraints. In each stage of Powell algorithm, firstly, searching along known n directions in sequence to obtain a best point, and then searching along the direction connecting the initial point and the best point in the stage to obtain the best point in the stage. The iteration of the next stage begins after replacing one of the first n directions with the last search direction. The optimal solution of all the screws (ɸ, theta, beta) in the universal head screw is obtained by the method, so that the curvature change rate value of the fitted spline curve is minimum, the nail rod reaches the smoothest state, and a target spline curve is generated, as shown in fig. 11, and fig. 11 is a schematic diagram of the target spline curve in the embodiment of the invention.
In the embodiment of the invention, the nail rod parameter data are obtained, and the curve parameter of each universal head screw is calculated according to the nail rod parameter data, the parameter attributes of a plurality of universal head screws and the position data of the plurality of universal head screws, wherein an optimization model is established by adopting a spherical coordinate system, the number of unknown variables is reduced, the constraint condition is simplified, the optimization problem is easier to solve, the curvature change rate is used as a spline curve smoothness evaluation index, the sum of all sections of spline curves is used as a target function, the aim of increasing the overall smoothness of the curve is fulfilled, the optimization model is an effective direct search method, the complex target function can still be efficiently solved, and the optimal universal head placing angle can be determined. The optimized target spline curve is smoother, less in twisting and hollow and more suitable for nail rods in practical application.
With reference to fig. 3, the spline curve generating method in the embodiment of the present invention is described above, and a spline curve generating apparatus in the embodiment of the present invention is described below, where an embodiment of the spline curve generating apparatus in the embodiment of the present invention includes:
the acquisition module 301 is configured to acquire nail setting scheme data of a target vertebral body, and analyze the nail setting scheme data to obtain multiple universal head screw parameter attributes and multiple universal head screw position data;
the calculation module 302 is configured to obtain nail rod parameter data, and calculate a curve parameter of each universal head screw according to the nail rod parameter data, the multiple universal head screw parameter attributes, and the multiple universal head screw position data;
the fitting module 303 is configured to perform spline curve fitting on the curve parameter of each universal head screw according to the position data of the plurality of universal head screws to obtain an initial spline curve, and calculate a curvature change rate of the initial spline curve;
and the generating module 304 is configured to invoke a preset optimization model to calculate an optimal solution of the initial spline according to the curvature change rate, so as to generate a target spline.
In the embodiment of the invention, the parameter data of the nail rod is obtained, and the curve parameter of each universal head screw is calculated according to the parameter data of the nail rod, the parameter attributes of a plurality of universal head screws and the position data of the universal head screws, wherein an optimized model is established by adopting a spherical coordinate system, the number of unknown variables is reduced, constraint conditions are simplified, the optimization problem is easier to solve, the curvature change rate is used as a spline curve smoothness evaluation index, the sum of all sections of spline curves is used as a target function, the aim of increasing the overall smoothness of the curve is achieved, the optimized model is adopted and is an effective direct searching method, the complex target function can still be efficiently solved, and the optimal universal head placing angle can be further solved. The optimized target spline curve is smoother, less in twisting and hollow and more suitable for nail rods in practical application.
Referring to fig. 4, another embodiment of the spline curve generating apparatus according to the embodiment of the present invention includes:
the acquisition module 301 is configured to acquire nail setting scheme data of a target vertebral body, and analyze the nail setting scheme data to obtain multiple universal head screw parameter attributes and multiple universal head screw position data;
the calculation module 302 is configured to obtain nail rod parameter data, and calculate a curve parameter of each universal head screw according to the nail rod parameter data, the multiple universal head screw parameter attributes, and the multiple universal head screw position data;
the fitting module 303 is configured to perform spline curve fitting on the curve parameter of each universal head screw according to the position data of the plurality of universal head screws to obtain an initial spline curve, and calculate a curvature change rate of the initial spline curve;
and the generating module 304 is configured to invoke a preset optimization model to calculate an optimal solution of the initial spline according to the curvature change rate, so as to generate a target spline.
Optionally, the calculating module 302 further includes:
a processing unit 3021 configured to obtain staple bar parameter data, wherein the staple bar parameter data comprises: the radius of the nail rod; respectively extracting the universal head rotation spherical center coordinates in the position data of each universal head screw; respectively extracting the thickness of the bottom end of the screw cap in the parameter attribute of each universal head screw; calculating a target distance according to the thickness of the bottom end of the screw cap, the radius of the nail rod and the distance from a preset sphere center to the bottom end of the screw cap; generating a target point coordinate according to the target distance and the universal head rotating spherical center coordinate;
a generating unit 3022 configured to generate a curve parameter for each universal head screw according to the target point coordinates.
Optionally, the generating unit 3022 is specifically configured to: acquiring a curve starting point and a curve ending point corresponding to a screw cap of each universal head screw; generating coordinate information corresponding to the curve starting point and the curve ending point based on the target point coordinates to obtain starting point coordinate information and ending point coordinate information; and taking the coordinate information of the starting point, the coordinate information of the ending point and the coordinate information of the target point as the curve parameters of each universal head screw.
Optionally, the fitting module 303 further includes:
the arrangement unit 3031 is configured to sequentially arrange the multiple universal head screws according to the multiple universal head screw position data to obtain an arrangement result;
a fitting unit 3032, configured to perform spline curve fitting on the curve parameter of each universal head screw according to the arrangement result to obtain an initial spline curve;
a calculating unit 3033, configured to segment the initial spline curve to obtain a plurality of segmental spline curves, and perform curvature change calculation on the plurality of segmental spline curves to obtain a curvature change rate.
Optionally, the calculating unit 3033 further includes:
the segmentation subunit is used for segmenting the initial spline curve by adopting a preset interpolation method to obtain a plurality of segment spline curves;
the calculating subunit is used for respectively calculating the curvature change of each segment of spline curve to obtain the curvature change rate of each segment of spline curve;
and the addition subunit is used for adding the curvature change rate of each segment of spline curve to obtain the curvature change rate of the initial spline curve.
Optionally, the calculation subunit is specifically configured to: acquiring the arc length of each segment of spline curve; calculating the curvature of each segment spline curve according to the arc length; and carrying out curvature change calculation on each segment of spline curve according to the curvature of each segment of spline curve to obtain the curvature change rate of each segment of spline curve.
Optionally, the generating module 304 is specifically configured to: calling a preset optimization model to carry out segmental search on the initial spline curve to obtain the best point of each segment; and performing optimal solution calculation on the initial spline curve according to the curvature change rate so as to minimize the curvature change rate of the initial spline curve and generate a target spline curve.
In the embodiment of the invention, the nail rod parameter data are obtained, and the curve parameter of each universal head screw is calculated according to the nail rod parameter data, the parameter attributes of a plurality of universal head screws and the position data of the plurality of universal head screws, wherein an optimization model is established by adopting a spherical coordinate system, the number of unknown variables is reduced, the constraint condition is simplified, the optimization problem is easier to solve, the curvature change rate is used as a spline curve smoothness evaluation index, the sum of all sections of spline curves is used as a target function, the aim of increasing the overall smoothness of the curve is fulfilled, the optimization model is an effective direct search method, the complex target function can still be efficiently solved, and the optimal universal head placing angle can be determined. The optimized target spline has smoother curve, less twisting and hollow and better fit with the nail rod in practical application.
Fig. 3 and 4 describe the spline curve generation device in the embodiment of the present invention in detail from the perspective of the modular functional entity, and the spline curve generation device in the embodiment of the present invention is described in detail from the perspective of hardware processing.
Fig. 5 is a schematic structural diagram of a spline curve generation apparatus, where the spline curve generation apparatus 500 may have a relatively large difference due to different configurations or performances, and may include one or more processors (CPUs) 510 (e.g., one or more processors), a memory 520, and one or more storage media 530 (e.g., one or more mass storage devices) for storing applications 533 or data 532. Memory 520 and storage media 530 may be, among other things, transient storage or persistent storage. The program stored in the storage medium 530 may include one or more modules (not shown), each of which may include a series of instruction operations in the spline curve generation apparatus 500. Still further, processor 510 may be configured to communicate with storage medium 530 to execute a series of instruction operations in storage medium 530 on spline curve generation device 500.
The spline curve generating device 500 may also include one or more power supplies 540, one or more wired or wireless network interfaces 550, one or more input-output interfaces 560, and/or one or more operating systems 531, such as Windows server, mac OS X, unix, linux, freeBSD, and the like. Those skilled in the art will appreciate that the spline-curve generating device structure shown in fig. 5 does not constitute a limitation of the spline-curve generating device, and may include more or fewer components than shown, or some components may be combined, or a different arrangement of components.
The present invention also provides a spline curve generation apparatus including a memory and a processor, the memory having stored therein computer readable instructions, which, when executed by the processor, cause the processor to execute the steps of the spline curve generation method in the above embodiments.
The present invention also provides a computer readable storage medium, which may be a non-volatile computer readable storage medium, which may also be a volatile computer readable storage medium, having stored therein instructions, which when run on a computer, cause the computer to perform the steps of the spline curve generation method.
It is clear to those skilled in the art that, for convenience and brevity of description, the specific working processes of the above-described systems, apparatuses and units may refer to the corresponding processes in the foregoing method embodiments, and are not described herein again.
The integrated unit, if implemented in the form of a software functional unit and sold or used as a stand-alone product, may be stored in a computer readable storage medium. Based on such understanding, the technical solution of the present invention may be embodied in the form of a software product, which is stored in a storage medium and includes instructions for causing a computer device (which may be a personal computer, a server, or a network device) to execute all or part of the steps of the method according to the embodiments of the present invention. And the aforementioned storage medium includes: various media capable of storing program codes, such as a usb disk, a removable hard disk, a read-only memory (ROM), a Random Access Memory (RAM), a magnetic disk, or an optical disk.
The above-mentioned embodiments are only used for illustrating the technical solutions of the present invention, and not for limiting the same; although the present invention has been described in detail with reference to the foregoing embodiments, it should be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; and such modifications or substitutions do not depart from the spirit and scope of the corresponding technical solutions of the embodiments of the present invention.
Claims (9)
1. A spline curve generation method, characterized by comprising:
acquiring nail placing scheme data of a target vertebral body, and analyzing the nail placing scheme data to obtain a plurality of universal head screw parameter attributes and a plurality of universal head screw position data;
acquiring nail rod parameter data, and calculating curve parameters of each universal head screw according to the nail rod parameter data, the parameter attributes of the universal head screws and the position data of the universal head screws; wherein, the acquiring of the nail rod parameter data and the calculating of the curve parameter of each universal head screw according to the nail rod parameter data, the plurality of universal head screw parameter attributes and the plurality of universal head screw position data comprise: acquiring nail rod parameter data, wherein the nail rod parameter data comprises: the radius of the nail rod; respectively extracting the universal head rotation spherical center coordinates in the position data of each universal head screw; respectively extracting the thickness of the bottom end of the nut in the parameter attribute of each universal head screw; calculating a target distance according to the thickness of the bottom end of the nut, the radius of the nail rod and the distance from a preset spherical center to the bottom end of the nut; generating a target point coordinate according to the target distance and the universal head rotating spherical center coordinate; generating a curve parameter of each universal head screw according to the target point coordinates;
spline curve fitting is carried out on curve parameters of each universal head screw according to the position data of the universal head screws to obtain an initial spline curve, and the curvature change rate of the initial spline curve is calculated;
and calling a preset optimization model to calculate the optimal solution of the initial spline curve according to the curvature change rate, and generating a target spline curve.
2. A spline curve generation method according to claim 1, wherein the generating curve parameters for each universal head screw according to the target point coordinates comprises:
acquiring a curve starting point and a curve ending point corresponding to a screw cap of each universal head screw;
generating coordinate information corresponding to the curve starting point and the curve ending point based on the target point coordinates to obtain starting point coordinate information and ending point coordinate information;
and taking the coordinate information of the starting point, the coordinate information of the ending point and the coordinate information of the target point as the curve parameters of each universal head screw.
3. The spline curve generation method according to claim 1, wherein the spline curve fitting a curve parameter of each of the universal head screws based on the plurality of universal head screw position data to obtain an initial spline curve, and calculating a curvature change rate of the initial spline curve includes:
sequentially arranging the universal head screws according to the position data of the universal head screws to obtain an arrangement result;
spline curve fitting is carried out on the curve parameters of each universal head screw according to the arrangement result to obtain an initial spline curve;
and segmenting the initial spline curve to obtain a plurality of segmental spline curves, and carrying out curvature change calculation on the plurality of segmental spline curves to obtain the curvature change rate.
4. A spline generation method according to claim 3, wherein the segmenting the initial spline to obtain a plurality of segmental splines and performing curvature change calculation on the plurality of segmental splines to obtain a curvature change rate of the initial spline comprises:
segmenting the initial spline curve by adopting a preset interpolation method to obtain a plurality of segment spline curves;
respectively carrying out curvature change calculation on each segment of spline curve to obtain the curvature change rate of each segment of spline curve;
and adding the curvature change rate of each segment of spline curve to obtain the curvature change rate of the initial spline curve.
5. A spline curve generation method according to claim 4, wherein said separately performing curvature change calculation on each segment of the spline curve to obtain a curvature change rate of each segment of the spline curve comprises:
acquiring the arc length of each segment of spline curve;
calculating the curvature of each segment spline curve according to the arc length;
and carrying out curvature change calculation on each segment of spline curve according to the curvature of each segment of spline curve to obtain the curvature change rate of each segment of spline curve.
6. A spline curve generation method according to any one of claims 1 to 5, wherein the generating a target spline curve by using a preset optimization model to calculate an optimal solution for the initial spline curve based on the curvature change rate comprises:
calling a preset optimization model to carry out segmental search on the initial spline curve to obtain the best point of each segment;
and performing optimal solution calculation on the initial spline curve according to the curvature change rate so as to minimize the curvature change rate of the initial spline curve and generate a target spline curve.
7. A spline curve generation apparatus, characterized by comprising:
the acquisition module is used for acquiring the nail placing scheme data of the target vertebral body and analyzing the nail placing scheme data to obtain a plurality of universal head screw parameter attributes and a plurality of universal head screw position data;
the calculation module is used for acquiring nail rod parameter data and calculating a curve parameter of each universal head screw according to the nail rod parameter data, the parameter attributes of the universal head screws and the position data of the universal head screws; wherein, the acquiring of the nail rod parameter data and the calculating of the curve parameter of each universal head screw according to the nail rod parameter data, the plurality of universal head screw parameter attributes and the plurality of universal head screw position data comprise: acquiring nail rod parameter data, wherein the nail rod parameter data comprises: the radius of the nail rod; respectively extracting the universal head rotation spherical center coordinates in the position data of each universal head screw; respectively extracting the thickness of the bottom end of the screw cap in the parameter attribute of each universal head screw; calculating a target distance according to the thickness of the bottom end of the screw cap, the radius of the nail rod and the distance from a preset sphere center to the bottom end of the screw cap; generating a target point coordinate according to the target distance and the universal head rotating spherical center coordinate; generating a curve parameter of each universal head screw according to the target point coordinates;
the fitting module is used for carrying out spline curve fitting on curve parameters of each universal head screw according to the position data of the universal head screws to obtain an initial spline curve and calculating the curvature change rate of the initial spline curve;
and the generating module is used for calling a preset optimization model to calculate the optimal solution of the initial spline curve according to the curvature change rate so as to generate a target spline curve.
8. A spline curve generation apparatus, characterized by comprising: a memory and at least one processor, the memory having instructions stored therein;
the at least one processor invokes the instructions in the memory to cause the spline curve generation device to perform the spline curve generation method of any of claims 1-6.
9. A computer readable storage medium having instructions stored thereon, which when executed by a processor implement the spline curve generation method of any one of claims 1-6.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202211188451.3A CN115272525B (en) | 2022-09-28 | 2022-09-28 | Spline curve generation method, device, equipment and storage medium |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202211188451.3A CN115272525B (en) | 2022-09-28 | 2022-09-28 | Spline curve generation method, device, equipment and storage medium |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN115272525A CN115272525A (en) | 2022-11-01 |
| CN115272525B true CN115272525B (en) | 2022-12-09 |
Family
ID=83756813
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202211188451.3A Active CN115272525B (en) | 2022-09-28 | 2022-09-28 | Spline curve generation method, device, equipment and storage medium |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN115272525B (en) |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN201073333Y (en) * | 2007-09-17 | 2008-06-18 | 郑琦 | Iliosacral joint anatomizing type steel plate internal fixation device |
| EP3788978A1 (en) * | 2019-09-04 | 2021-03-10 | Globus Medical, Inc. | Methods providing bend plans for surgical rods and related controllers and computer program products |
| CN113576665A (en) * | 2021-03-02 | 2021-11-02 | 马佐尔机器人有限公司 | Device, method and system for intraoperative screw planning |
| CN114209427A (en) * | 2020-07-10 | 2022-03-22 | 格罗伯斯医疗有限公司 | Intraoperative alignment assessment system and method |
Family Cites Families (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US8549888B2 (en) * | 2008-04-04 | 2013-10-08 | Nuvasive, Inc. | System and device for designing and forming a surgical implant |
| US20200405395A1 (en) * | 2017-07-03 | 2020-12-31 | Spine Align, Llc | Intraoperative alignment assessment system and method |
| US11925417B2 (en) * | 2019-04-02 | 2024-03-12 | Medicrea International | Systems, methods, and devices for developing patient-specific spinal implants, treatments, operations, and/or procedures |
-
2022
- 2022-09-28 CN CN202211188451.3A patent/CN115272525B/en active Active
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN201073333Y (en) * | 2007-09-17 | 2008-06-18 | 郑琦 | Iliosacral joint anatomizing type steel plate internal fixation device |
| EP3788978A1 (en) * | 2019-09-04 | 2021-03-10 | Globus Medical, Inc. | Methods providing bend plans for surgical rods and related controllers and computer program products |
| CN114209427A (en) * | 2020-07-10 | 2022-03-22 | 格罗伯斯医疗有限公司 | Intraoperative alignment assessment system and method |
| CN113576665A (en) * | 2021-03-02 | 2021-11-02 | 马佐尔机器人有限公司 | Device, method and system for intraoperative screw planning |
Also Published As
| Publication number | Publication date |
|---|---|
| CN115272525A (en) | 2022-11-01 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN110288675B (en) | Lane reference line construction method and device and storage medium | |
| WO2015002113A1 (en) | Method for fitting primitive shapes to a set of 3d points | |
| JPS6282486A (en) | Recognizing device for online handwritten graphic form | |
| CN105093926B (en) | A kind of Optimized Matching combined method of iterative learning control reference locus | |
| CN109408765B (en) | Intelligent matching tracking sparse reconstruction method based on quasi-Newton method | |
| CN104112289A (en) | Three-dimensional object point cloud registration method based on parallel cascaded EM-ICP | |
| CN113486844B (en) | Horizontal wind shear position judgment method and device, electronic equipment and storage medium | |
| CN115272525B (en) | Spline curve generation method, device, equipment and storage medium | |
| CN115794414B (en) | Satellite earth-to-earth view analysis method, device and equipment based on parallel computing | |
| CN108804391A (en) | A kind of building method and system of interpolation curve or curved surface based on B-spline | |
| CN117274339A (en) | Point cloud registration method based on improved ISS-3DSC characteristics combined with ICP | |
| CN109035311B (en) | Automatic registration and internal fixation steel plate pre-bending modeling method for curved bone fracture | |
| CN109975320B (en) | Cylindrical curved surface image acquisition method, system and device based on machine vision | |
| CN112802089B (en) | Point cloud skeleton line extraction method and system based on automatic bifurcation quantity estimation | |
| CN107423507B (en) | Complex non-node load action rigid frame structure internal force diagram and deformation diagram drawing method | |
| CN113658194A (en) | Point cloud splicing method and device based on reference object and storage medium | |
| Fiestas et al. | RPA and L-system based synthetic data generator for cost-efficient deep learning model training | |
| JP4140338B2 (en) | Summary map generation device, road map conversion device, program, and summary map service system | |
| CN111445525A (en) | Camera installation position layout method, device, equipment and storage medium | |
| CN115881211B (en) | Protein sequence alignment method, protein sequence alignment device, computer equipment and storage medium | |
| CN111325854B (en) | Shape model correction device, shape model correction method, and storage medium | |
| CN115690339A (en) | High-precision airspace perspective analysis method in cylindrical coordinate space | |
| CN112991300A (en) | Single-wood skeleton extraction and visualization method based on neighborhood characteristics | |
| CN113103239B (en) | Robot attitude trajectory generation method and device and storage medium | |
| Cheng et al. | Sequential pattern learning via kernel alignment |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |