A method and device for constructing a personalized brace model for 3D printing

Abstract

The present invention relates to a method and device for constructing a personalized brace model for 3D printing, the method comprising: obtaining a three-dimensional mesh model of a patient; identifying multiple feature points from the three-dimensional mesh model based on a KD tree and a principal component analysis method; generating an initial curve on the surface of the three-dimensional mesh model according to the multiple feature points; iterating the initial curve based on the geodesic curvature of each point in the initial curve to obtain a smooth curve; and trimming the three-dimensional mesh model through the smooth curve to obtain a brace model. The present invention achieves the needs of personalized brace design based on mesh model trimming of generated curves, simplifies the mesh model construction process, and effectively solves the problems of complex design and long modeling time of current 3D printed brace models.

Description

Technical Field

[0001] The present invention belongs to the technical field of 3D printing, and in particular relates to a method and device for constructing a personalized brace model for 3D printing. Background Art

[0002] Additive manufacturing, commonly known as 3D printing, is based on the discrete-accumulation principle and is driven by three-dimensional data of parts. It is a technology that stacks special metal materials, non-metallic materials and medical biomaterials layer by layer through extrusion, sintering, melting, photocuring and spraying to produce physical objects.

[0003] At present, additive manufacturing technology is being used more and more widely in rehabilitation braces. It can manufacture objects of any complex shape. Combined with reverse modeling technology, it can design and manufacture new medical device products with high functionality, comfort and safety. It has obvious advantages, especially in the field of personalized customized rehabilitation braces.

[0004] In the existing brace design process, a 3D scanner is generally used to obtain the contour data of the patient's joints or torso, and then the contour model is adjusted and corrected through computer software. Then the brace model is constructed, and then 3D printing technology is used for production. However, when designing personalized braces for different patients, repeated modeling processes are required, and the modeling process is heavily dependent on the level and experience of technicians. The modeling accuracy of different technicians varies greatly, and the modeling efficiency needs to be improved. Summary of the invention

[0005] In order to solve the problems of complex design and long modeling time of current 3D printed brace models, a first aspect of the present invention provides a method for constructing a personalized brace model for 3D printing, comprising: obtaining a three-dimensional mesh model of a patient; identifying multiple feature points from the three-dimensional mesh model based on a KD tree and a principal component analysis method; generating an initial curve on the surface of the three-dimensional mesh model according to the multiple feature points; iterating the initial curve based on the geodesic curvature of each point in the initial curve to obtain a smooth curve; and trimming the three-dimensional mesh model by the smooth curve to obtain a brace model.

[0006] In some embodiments of the present invention, the identifying of multiple feature points from the three-dimensional mesh model based on the KD tree and principal component analysis method includes: selecting multiple initial points as a feature point identification area; based on the KD tree, searching for a preset number of points closest to each initial point in the feature point identification area; and using the principal component analysis method, identifying multiple feature points from a point set consisting of a preset number of points closest to each initial point.

[0007] Furthermore, generating an initial curve on the surface of the three-dimensional mesh model according to the multiple feature points includes: adding one or more vertices to the three-dimensional mesh model based on the user's personalized needs and the multiple feature points; and generating an initial curve on the surface of the three-dimensional mesh model by using the Dijkstra algorithm based on the one or more vertices.

[0008] In some embodiments of the present invention, the initial curve is iterated based on the geodesic curvature of each point in the initial curve to obtain a smooth curve, including: in each iteration step: based on the adjacent triangles of each point in the initial curve, the geodesic curvature and the expected geodesic curvature of each point are calculated; according to the positional relationship of each point in the initial curve in the three-dimensional mesh model, each point is moved or the initial curve is segmented; the iteration step is repeated until the number of iterations reaches a preset value or the geodesic curvature of the current point is equal to the expected geodesic curvature.

[0009] Furthermore, the method of moving each point or splitting the initial curve according to the positional relationship of each point in the three-dimensional mesh model includes: if a point in the initial curve is located on the edge of the three-dimensional mesh model, moving the point along two adjacent edges of the three-dimensional mesh model; if a point in the initial curve is located on the vertex of the three-dimensional mesh model, adding new curve segments and vertices according to the adjacent triangles of the point to split the initial curve.

[0010] In the above embodiment, the three-dimensional mesh model is clipped by the smooth curve to obtain the brace model, which includes: extracting one or more triangular facet groups intersected by the smooth curve; constructing a discriminant plane based on two consecutive curve points on each triangular facet, and dividing each triangular facet according to the normal vector of the discriminant plane; and generating the brace model by reorganizing the mesh based on the divided multiple triangular facets.

[0011] According to a second aspect of the present invention, a personalized brace model construction device for 3D printing is provided, comprising: an acquisition module for acquiring a three-dimensional mesh model of a patient; a generation module for identifying a plurality of feature points from the three-dimensional mesh model based on a KD tree and a principal component analysis method; and generating an initial curve on the surface of the three-dimensional mesh model according to the plurality of feature points; an iteration module for iterating the initial curve based on the geodesic curvature of each point in the initial curve to obtain a smooth curve; and a clipping module for clipping the three-dimensional mesh model through the smooth curve to obtain a brace model.

[0012] Furthermore, the generation module includes: a selection unit for selecting multiple initial points as a feature point recognition area; a search unit for searching a preset number of points closest to each initial point in the feature point recognition area based on a KD tree; and an identification unit for identifying multiple feature points from a point set consisting of a preset number of points closest to each initial point using a principal component analysis method.

[0013] In a third aspect of the present invention, an electronic device is provided, comprising: one or more processors; a storage device for storing one or more programs, wherein when the one or more programs are executed by the one or more processors, the one or more processors implement the personalized brace model construction method for 3D printing provided in the first aspect of the present invention.

[0014] According to a fourth aspect of the present invention, a computer-readable medium is provided, on which a computer program is stored, wherein when the computer program is executed by a processor, the method for constructing a personalized brace model for 3D printing provided in the first aspect of the present invention is implemented.

[0015] The beneficial effects of the present invention are:

[0016] The present invention relates to a method and device for constructing a personalized brace model for 3D printing, the method comprising: obtaining a three-dimensional mesh model of a patient; identifying multiple feature points from the three-dimensional mesh model based on a KD tree and a principal component analysis method; generating an initial curve on the surface of the three-dimensional mesh model according to the multiple feature points; iterating the initial curve based on the geodesic curvature of each point in the initial curve to obtain a smooth curve; and clipping the three-dimensional mesh model by the smooth curve to obtain a brace model. It can be seen that when the present invention designs personalized braces for different patients, it can generate smooth curves on the mesh model while ensuring that the curves are strictly constrained on the mesh model surface, and the modeling process does not need to be overly dependent on the level and experience of technicians, and the modeling efficiency is high. Compared with the Boolean cutting operation in the existing modeling process, by clipping the mesh model on the basis of generating the mesh curve, the modeling process of the complex mesh model can be effectively simplified, and the modeling accuracy is high and the robustness is good. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 A schematic diagram of a basic process of a method for constructing a personalized brace model for 3D printing in some embodiments of the present invention;

[0018] Figure 2 A schematic diagram of a specific process of a method for constructing a personalized brace model for 3D printing in some embodiments of the present invention;

[0019] Figure 3A schematic diagram of a curve point adjacent to a triangular facet in some embodiments of the present invention;

[0020] Figure 4 Schematic diagram of curve point splitting in some embodiments of the present invention;

[0021] Figure 5 It is a schematic diagram of a construction plane in some embodiments of the present invention;

[0022] Figure 6 is a schematic diagram of an original grid model in some embodiments of the present invention;

[0023] Figure 7 is a schematic diagram of a clipped grid model in some embodiments of the present invention;

[0024] Figure 8 A schematic diagram of a curve generated by reference feature points of a mesh model in some embodiments of the present invention;

[0025] Fig. 9 It is a schematic structural diagram of a personalized brace model building device for 3D printing in some embodiments of the present invention;

[0026] Fig.10 It is a schematic diagram of the structure of an electronic device in some embodiments of the present invention. DETAILED DESCRIPTION

[0027] The principles and features of the present invention are described below in conjunction with the accompanying drawings. The examples given are only used to explain the present invention and are not used to limit the scope of the present invention.

[0028] refer to Figure 1 and Figure 2 In a first aspect of the present invention, a method for constructing a personalized brace model for 3D printing is provided, comprising: S100. Acquire a three-dimensional mesh model of a patient; S200. Based on a KD tree and a principal component analysis method, identify multiple feature points from the three-dimensional mesh model; generate an initial curve on the surface of the three-dimensional mesh model according to the multiple feature points; S300. Based on the geodesic curvature of each point in the initial curve, iterate the initial curve to obtain a smooth curve; S400. Trim the three-dimensional mesh model by the smooth curve to obtain a brace model.

[0029] In step S100 of some embodiments of the present invention, a three-dimensional mesh model of the patient is obtained; generally, the three-dimensional mesh model in stl format is read; it should be noted that the three-dimensional mesh model of the patient mainly refers to the contour model of the patient's joints or torso, or the contour model of the human body part related to the brace.

[0030] In step S200 of some embodiments of the present invention, identifying a plurality of feature points from the three-dimensional mesh model based on the KD tree and the principal component analysis method includes:

[0031] S201. Select multiple initial points as feature point recognition areas;

[0032] Specifically, those skilled in the art determine to select an initial point on the model as a feature point recognition area based on the elements of the brace and kinematics knowledge in related fields;

[0033] S202. Based on the KD tree, searching for a preset number of points closest to each initial point in the feature point recognition area;

[0034] S203. Using the principal component analysis method, multiple feature points are identified from a point set consisting of a preset number of points closest to each initial point.

[0035] Specifically, KdTree is used to find the 300 points closest to the point and store them in the point set. The maximum principal component vector in the point set is calculated through PCA principal component analysis. All points in the point set are projected onto the maximum principal component vector, and the extreme points (extreme points) on the vector are used as feature points.

[0036] In step S200 of some embodiments of the present invention, generating an initial curve on the surface of the three-dimensional mesh model according to the plurality of feature points includes:

[0037] S204. Add one or more vertices to the three-dimensional mesh model based on the user's personalized needs and the plurality of feature points;

[0038] Specifically, the initial curve is interactively determined by technicians, who add vertices to the mesh according to the design intent with reference to the identified feature points;

[0039] S205. Based on the one or more vertices, generate an initial curve on the surface of the three-dimensional mesh model by using the Dijkstra algorithm.

[0040] Specifically, the Dijkstra algorithm is used to generate the curve, and the obtained curve is composed of a series of vertices connected by edges.

[0041] It can be understood that the feature points in the process of generating the initial curve in steps S204 and S205 are regarded as reference points, and the initial curve is generated on the model surface by referring to the feature points.

[0042] In step S300 of some embodiments of the present invention, iterating the initial curve based on the geodesic curvature of each point in the initial curve to obtain a smooth curve includes:

[0043] S301. Based on the adjacent triangles of each point in the initial curve, calculate the geodesic curvature and the expected geodesic curvature of each point;

[0044] S302. According to the positional relationship of each point in the initial curve in the three-dimensional mesh model, each point is moved or the initial curve is segmented;

[0045] S303. Repeat all the above steps until the number of iterations reaches a preset value or the geodesic curvature of the current point is equal to the expected geodesic curvature.

[0046] refer to Figure 3 , point The adjacent triangles of are unfolded in the plane. and are the previous point and the next point on the curve respectively, and calculate and Angle , and point The total angle and , and All sides within the angle are points The corresponding edge when splitting. Point The geodesic curvature of The calculation formula is:

[0047] ,

[0048] By using different coefficients For different curve points Calculate expected geodesic curvature :

[0049] .

[0050] During this process, the points on the curve can move freely along the edge of the mesh model, but it is necessary to ensure that each curve point always stays on the edge. Therefore, the value range of t is [0,1]. In the special case where the curve point coincides with the vertex, corresponding processing is required to ensure that each point on the curve does not move to the vertex of the patch.

[0051] Furthermore, in step S302, the moving of each point or the segmentation of the initial curve according to the positional relationship of each point in the three-dimensional mesh model includes: if a point in the initial curve is located on the edge of the three-dimensional mesh model, the point is moved along two adjacent edges of the three-dimensional mesh model; if a point in the initial curve is located on a vertex of the three-dimensional mesh model, new curve segments and vertices are added according to the adjacent triangles of the point to segment the initial curve.

[0052] Specifically, the curve point There are two situations when smoothing: curve points On the edge or on the vertex. When the curve point When on the edge, the curve point Can move in two directions; when the curve point When at a vertex, new curve segments need to be added during the smooth iteration process. By adding new vertices, the original curve is divided into multiple segments to participate in the next iteration.

[0053] Continue to refer Figure 4 , when the curve point When on a vertex, the curve point is split into multiple curve points, each of which lies on the edge associated with the vertex. A curve smoothing step in an iteration consists of splitting and moving all curve points. When smoothing, the curve points The adjacent triangles of are extracted, and the points The split points are moved on the corresponding edges so that the geodesic curvature at this time satisfies the expected geodesic curvature.

[0054] After each iteration, the position of the point on the surface curve is checked to see if it appears in a reasonable position and whether the curvature of the curve meets the requirements, so as to decide whether to proceed to the next iteration. Therefore, the maximum number of iterations is set to 300 steps, and the optimization iteration termination condition is: curve point The current geodesic curvature satisfies the expected geodesic curvature.

[0055] In a specific embodiment of step S300, the specific steps of iteration include:

[0056] S312: reset the number of curve points, i=0, and execute S313;

[0057] S313: Determine the number of current curve points Is it less than the maximum number of points on the curve? If yes, execute S314; if not, execute step S505;

[0058] S314: Take the Points Calculate the adjacent triangles and the new position of the point , execute S313;

[0059] S315: Determine whether the iteration process meets the termination condition. If yes, the iteration ends; if no, execute S316;

[0060] S316: Process the critical point, increase the number of iterations by 1, and execute S311.

[0061] In step S400 of the above embodiment, the step of trimming the three-dimensional mesh model by the smooth curve to obtain the brace model includes:

[0062] S401. Extract one or more triangular facet groups where smooth curves intersect;

[0063] S402. Constructing a discriminant plane based on two consecutive curve points on each triangular face, and segmenting each triangular face according to the normal vector of the discriminant plane;

[0064] S403. Generate a brace model by reorganizing the meshes based on the segmented multiple triangular facets.

[0065] refer to Figure 5 , there are two consecutive curve points on each triangle and , passing through point and Construct a plane whose normal vector is the vector It is obtained by cross-multiplying the triangle normal vector.

[0066] Usage Vector and Point To represent the plane:

[0067] ,

[0068] vertex Discriminant of the relationship between position and plane :

[0069] ,

[0070] Discriminant Greater than 0, indicating a vertex In the direction of the positive normal vector of the plane; discriminant Less than 0, indicating a vertex In the negative normal direction of the plane. Therefore, by substituting the vertices of the triangle group into the corresponding discriminant, we can get the position relationship between each triangle vertex and the corresponding plane, so that the vertices of the triangle group are divided into two parts of point sets with the curve as the boundary. Combine the curve point set to triangulate it, regenerate the triangle, and generate the cropped model by reorganizing the mesh.

[0071] Without loss of generality, refer to Figure 8 , cutting and trimming the mesh model based on the mesh model curve to obtain an optimized mesh model; saving the optimized mesh model data in stl format; and printing the 3D model based on the optimized mesh model.

[0072] refer to Figures 6 to 8 In a specific embodiment of the present invention, the following steps are included:

[0073] S1. Read the ankle joint mesh model in stl format;

[0074] S2. The technician selects an initial point on the ankle model as the feature point recognition area, uses KdTree to find the 300 points closest to the point and stores them in the point set, calculates the maximum principal component vector in the point set through PCA principal component analysis, projects all points in the point set onto the maximum principal component vector, and uses the extreme points on the vector as feature points; the technician adds vertices with reference to the identified feature points, and then uses the Dijkstra algorithm between the vertices to obtain the initial curve;

[0075] S3. Iteratively smooth the initial curve by splitting the curve points and moving the curve points to meet the desired geodesic curvature position to generate a smooth curve;

[0076] S4. Cut and trim the mesh model based on the mesh model curve to obtain an optimized mesh model, save the optimized mesh model data in stl format; and print the 3D model based on the optimized mesh model.

[0077] It can be understood that the present invention cuts the brace mesh model based on the mesh curve, and the modeling process does not need to rely too much on the level and experience of the technician. Compared with the operations such as Boolean cutting in the existing modeling process, by cutting the mesh model based on the generated mesh curve, the modeling process of the complex mesh model can be effectively simplified, and the personalized brace design needs of different patients can be targeted, and the modeling accuracy and efficiency can be effectively improved.

[0078] Example 2

[0079] refer to Fig. 9 According to a second aspect of the present invention, a personalized brace model construction device 1 for 3D printing is provided, comprising: an acquisition module 11, for acquiring a three-dimensional mesh model of a patient; a generation module 12, for identifying a plurality of feature points from the three-dimensional mesh model based on a KD tree and a principal component analysis method; and generating an initial curve on the surface of the three-dimensional mesh model according to the plurality of feature points; an iteration module 13, for iterating the initial curve based on the geodesic curvature of each point in the initial curve to obtain a smooth curve; and a clipping module 14, for clipping the three-dimensional mesh model through the smooth curve to obtain a brace model.

[0080] Furthermore, the generation module 12 includes: a selection unit for selecting multiple initial points as a feature point recognition area; a search unit for searching for a preset number of points closest to each initial point in the feature point recognition area based on a KD tree; and an identification unit for identifying multiple feature points from a point set consisting of a preset number of points closest to each initial point using a principal component analysis method.

[0081] Example 3

[0082] refer to Fig.10 According to a third aspect of the present invention, an electronic device is provided, comprising: one or more processors; a storage device for storing one or more programs, wherein when the one or more programs are executed by the one or more processors, the one or more processors implement the personalized brace model construction method for 3D printing according to the first aspect of the present invention.

[0083] The electronic device 500 may include a processing device (e.g., a central processing unit, a graphics processing unit, etc.) 501, which can perform various appropriate actions and processes according to a program stored in a read-only memory (ROM) 502 or a program loaded from a storage device 508 into a random access memory (RAM) 503. In the RAM 503, various programs and data required for the operation of the electronic device 500 are also stored. The processing device 501, the ROM 502, and the RAM 503 are connected to each other via a bus 504. An input / output (I / O) interface 505 is also connected to the bus 504.

[0084] Typically, the following devices may be connected to the I / O interface 505: an input device 506 including, for example, a touch screen, a touch pad, a keyboard, a mouse, a camera, a microphone, an accelerometer, a gyroscope, etc.; an output device 507 including, for example, a liquid crystal display (LCD), a speaker, a vibrator, etc.; a storage device 508 including, for example, a hard disk, etc.; and a communication device 509. The communication device 509 may allow the electronic device 500 to communicate with other devices wirelessly or by wire to exchange data. Although Fig. 9 The electronic device 500 is shown with various devices, but it should be understood that it is not required to implement or possess all the devices shown. More or fewer devices may be implemented or possessed instead. Fig. 9 Each block shown in the figure may represent one device, or may represent multiple devices as required.

[0085] In particular, according to an embodiment of the present disclosure, the process described above with reference to the flowchart can be implemented as a computer software program. For example, an embodiment of the present disclosure includes a computer program product, which includes a computer program carried on a computer-readable medium, and the computer program includes a program code for executing the method shown in the flowchart. In such an embodiment, the computer program can be downloaded and installed from the network through a communication device 509, or installed from a storage device 508, or installed from a ROM 502. When the computer program is executed by the processing device 501, the above functions defined in the method of the embodiment of the present disclosure are executed. It should be noted that the computer-readable medium described in the embodiment of the present disclosure can be a computer-readable signal medium or a computer-readable storage medium or any combination of the above two. The computer-readable storage medium can be, for example, but not limited to, an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, device or device, or any combination of the above. More specific examples of computer-readable storage media may include, but are not limited to, an electrical connection with one or more conductors, a portable computer disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber, a portable compact disk read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the above. In an embodiment of the present disclosure, a computer-readable storage medium may be any tangible medium containing or storing a program that can be used by or in combination with an instruction execution system, an apparatus, or a device. In an embodiment of the present disclosure, a computer-readable signal medium may include a data signal propagated in a baseband or as part of a carrier wave, in which a computer-readable program code is carried. Such propagated data signals may take a variety of forms, including but not limited to electromagnetic signals, optical signals, or any suitable combination of the above. A computer-readable signal medium may also be any computer-readable medium other than a computer-readable storage medium, which may send, propagate, or transmit a program for use by or in combination with an instruction execution system, an apparatus, or a device. The program code embodied on the computer readable medium may be transmitted using any appropriate medium, including but not limited to: wire, optical cable, RF (radio frequency), etc., or any suitable combination of the foregoing.

[0086] The computer-readable medium may be included in the electronic device, or may exist independently without being installed in the electronic device. The computer-readable medium carries one or more computer programs. When the one or more programs are executed by the electronic device, the electronic device:

[0087] Computer program code for performing the operations of embodiments of the present disclosure may be written in one or more programming languages ​​or a combination thereof, including object-oriented programming languages, such as Java, Smalltalk, C++, Python, and conventional procedural programming languages, such as "C" or similar programming languages. The program code may be executed entirely on a user's computer, partially on a user's computer, as a separate software package, partially on a user's computer and partially on a remote computer, or entirely on a remote computer or server. In cases involving a remote computer, the remote computer may be connected to the user's computer via any type of network, including a local area network (LAN) or a wide area network (WAN), or may be connected to an external computer (e.g., via the Internet using an Internet service provider).

[0088] The flow chart and block diagram in the accompanying drawings illustrate the possible architecture, function and operation of the system, method and computer program product according to various embodiments of the present disclosure. In this regard, each box in the flow chart or block diagram can represent a module, a program segment or a part of a code, and the module, the program segment or a part of the code contains one or more executable instructions for realizing the specified logical function. It should also be noted that in some alternative implementations, the functions marked in the box can also occur in a different order from the order marked in the accompanying drawings. For example, two boxes represented in succession can actually be executed substantially in parallel, and they can sometimes be executed in the opposite order, depending on the functions involved. It should be noted that each box in the block diagram and / or flow chart, and the combination of the boxes in the block diagram and / or flow chart can be implemented with a dedicated hardware-based system that performs a specified function or operation, or can be implemented with a combination of dedicated hardware and computer instructions.

[0089] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for constructing a personalized brace model for 3D printing, characterized in that: include: Obtaining a three-dimensional mesh model of the patient; Based on the KD tree and principal component analysis method, multiple feature points are identified from the three-dimensional grid model: multiple initial points are selected as feature point identification areas; based on the KD tree, a preset number of points closest to each initial point are searched in the feature point identification area; Using principal component analysis, a plurality of feature points are identified from a point set consisting of a preset number of points closest to each initial point; an initial curve is generated on the surface of the three-dimensional mesh model according to the plurality of feature points; one or more vertices are added to the three-dimensional mesh model based on the personalized needs of the user and the plurality of feature points; and an initial curve is generated on the surface of the three-dimensional mesh model by using a Dijkstra algorithm based on the one or more vertices; Iterating the initial curve based on the geodesic curvature of each point in the initial curve to obtain a smooth curve; The three-dimensional mesh model is cut by the smooth curve to obtain a brace model: one or more triangular facet groups intersecting the smooth curve are extracted; each triangular facet has two consecutive curve points P i and P i+1 , passing through point P i and P i+1 Construct a plane whose normal vector is the vector P i P i+1 It is obtained by cross-producting the normal vector of the triangle face; A discriminant plane is constructed based on two consecutive curve points on each triangular face, and each triangular face is segmented according to the normal vector of the discriminant plane; wherein the normal vector ( n x, n y, ,n z, ) and dot P i ( x i, y i, ,z i, ) to represent the plane n x (x- x i )+ n y (y- y i )+ n z (z- z i )=0, The discriminant t(x,y,z) between the vertex (x,y,z) and the plane position is: t (x,y,z)= n x x + n y y+n z z- ( x i +y i +z i ), The discriminant t(x, y, z) is greater than 0, indicating that the vertex (x, y, z) is in the positive normal vector direction of the plane; the discriminant t(x, y, z) is less than 0, indicating that the vertex (x, y, z) is in the negative normal vector direction of the plane; by substituting the vertices of the triangular face group into the corresponding discriminant, the position relationship between each triangular face vertex and the corresponding plane is obtained, so that the vertices of the triangular face group are divided into two point sets with the curve as the boundary; based on the multiple triangular facets after segmentation, the brace model is generated by reorganizing the mesh, and the generating of the brace model by reorganizing the mesh based on the multiple triangular facets after segmentation includes: triangulating the curve point set in combination, regenerating the triangular facets, and generating the cropped model by reorganizing the mesh.

2. The method for constructing a personalized brace model for 3D printing according to claim 1, characterized in that: The step of iterating the initial curve based on the geodesic curvature of each point in the initial curve to obtain a smooth curve comprises: In each iteration step: based on the adjacent triangles of each point in the initial curve, the geodesic curvature and the expected geodesic curvature of each point are calculated; according to the positional relationship of each point in the initial curve in the three-dimensional mesh model, each point is moved or the initial curve is segmented; The iterative steps are repeated until the number of iterations reaches a preset value or the geodesic curvature of the current point is equal to the expected geodesic curvature.

3. The method for constructing a personalized brace model for 3D printing according to claim 2, characterized in that: The step of moving each point or segmenting the initial curve according to the positional relationship of each point in the initial curve in the three-dimensional mesh model comprises: If a point in the initial curve is located on the edge of the three-dimensional mesh model, the point is moved along two adjacent edges of the three-dimensional mesh model; If a point in the initial curve is located on a vertex of the three-dimensional mesh model, new curve segments and vertices will be added according to the adjacent triangles of the point to segment the initial curve.

4. A personalized brace model construction device for 3D printing, characterized in that: include: An acquisition module, used for acquiring a three-dimensional mesh model of a patient; A generation module is used to identify multiple feature points from the three-dimensional grid model based on a KD tree and a principal component analysis method: select multiple initial points as a feature point recognition area; based on the KD tree, search for a preset number of points closest to each initial point in the feature point recognition area; Using principal component analysis, a plurality of feature points are identified from a point set consisting of a preset number of points closest to each initial point; an initial curve is generated on the surface of the three-dimensional mesh model according to the plurality of feature points; one or more vertices are added to the three-dimensional mesh model based on the personalized needs of the user and the plurality of feature points; Based on the one or more vertices, generating an initial curve on the surface of the three-dimensional mesh model by using a Dijkstra algorithm; An iteration module, configured to iterate the initial curve based on the geodesic curvature of each point in the initial curve to obtain a smooth curve; The clipping module is used to: extract one or more triangular facets where smooth curves intersect; each triangular facet has two consecutive curve points P i and P i+1 , passing through point P i and P i+1 Construct a plane whose normal vector is the vector P i P i+1 It is obtained by cross-producting the normal vector of the triangle patch; A discriminant plane is constructed based on two consecutive curve points on each triangular face, and each triangular face is segmented according to the normal vector of the discriminant plane; wherein the normal vector ( n x, n y, ,n z, ) and dot P i ( x i, y i, ,z i, ) to represent the plane n x (x- x i )+ n y (y- y i )+ n z (z- z i )=0, The discriminant t(x,y,z) between the vertex (x,y,z) and the plane position is: t (x,y,z)= n x x + n y y+n z z- ( x i+ y i +z i ), The discriminant t(x, y, z) is greater than 0, indicating that the vertex (x, y, z) is in the positive normal vector direction of the plane; the discriminant t(x, y, z) is less than 0, indicating that the vertex (x, y, z) is in the negative normal vector direction of the plane; by substituting the vertices of the triangular face group into the corresponding discriminant, the position relationship between each triangular face vertex and the corresponding plane is obtained, so that the vertices of the triangular face group are divided into two point sets with the curve as the boundary; based on the multiple triangular facets after segmentation, the brace model is generated by reorganizing the mesh, and the generating of the brace model by reorganizing the mesh based on the multiple triangular facets after segmentation includes: triangulating the curve point set in combination, regenerating the triangular facets, and generating the cropped model by reorganizing the mesh.

5. An electronic device comprising: one or more processors; A storage device for storing one or more programs, when the one or more programs are executed by the one or more processors, so that the one or more processors implement the personalized brace model construction method for 3D printing as described in any one of claims 1 to 3.

6. A computer readable medium having a computer program stored thereon, wherein: When the computer program is executed by a processor, the method for constructing a personalized brace model for 3D printing according to any one of claims 1 to 3 is implemented.

Images