A 3D printing external fixation model partition expansion method, device and electronic device

Abstract

The present invention relates to a method, device and electronic device for partitioning and expanding an external fixation model in 3D printing. First, a target model, a plurality of target expansion partitions and a plurality of transition partitions are obtained. Then, the expansion direction vector of each expansion reference point is obtained according to the surface shape of the target model. Next, based on a preset expansion value, the transition expansion value of the transition partition is obtained according to the arrangement position relationship between the target expansion partition and the transition partition. Finally, each expansion reference point is expanded to obtain the target expansion model. Compared with the prior art, the present invention realizes the partitioning and expansion of the 3D printing external fixation model by using the expansion direction vector, the preset expansion value and the transition expansion value to expand the expansion reference point. And because the transition expansion value is obtained based on the preset expansion value, in addition to the target expansion partition meeting the requirements in the target expansion model, the expansion level of the transition partition also meets the expectation, greatly improving the fitting degree between the model and the patient.

Description

Technical Field

[0001] The present invention relates to the field of medical technology, and in particular to a method, device and electronic equipment for partition expansion of a 3D printed external fixation model. Background Art

[0002] Medical external fixation braces mainly play a role in fixing the damaged limb part of a patient, thereby reducing the movement of the damaged limb part and being beneficial to the recovery of the damaged part of the patient. Traditional external fixation braces such as plaster and splints have many disadvantages. For example, the fixed part of the plaster cannot be cleaned, and the tightness of the splint fixation depends on the doctor's experience. These factors have restricted the use of plaster and splints and promoted the development of the application of 3D printed external fixation braces in the medical field.

[0003] With the continuous development of the application of 3D printing in the medical field, 3D printed external fixation models can effectively reduce the disadvantages brought by previous plaster or splint fixation. There are now many 3D printing software, and the main functions include importing models, model expansion, model cutting, model slicing, etc., which can basically meet the needs of external fixation brace printing.

[0004] However, in the existing 3D printing related software, the model expansion function for the current 3D printed model can only expand the model as a whole, which may cause the printed external fixation brace to partially fit the patient's limb and partially not fit. Summary of the Invention

[0005] In view of this, it is necessary to provide a method, device and equipment for partition expansion of a 3D printed external fixation model to solve the problem in the prior art that only the whole model can be expanded, resulting in the situation that the printed external fixation brace may partially fit the patient's limb and partially not fit.

[0006] To achieve the above technical purpose, the present invention adopts the following technical solutions:

[0007] In a first aspect, the present invention provides a method for partition expansion of a 3D printed external fixation model, including:

[0008] Obtain a target model, a plurality of target expansion partitions and a plurality of transition partitions, the plurality of target expansion partitions are arranged on the target model along the material stacking direction of 3D printing, and the plurality of transition partitions are respectively located between two adjacent target expansion partitions;

[0009] Obtain the expansion reference points in the target model, and according to the surface shape of the target model, obtain the expansion direction vectors of each expansion reference point;

[0010] Obtain the preset expansion value of each of the target extended partitions, and based on the preset expansion value, obtain the transition expansion value of the transition partition according to the arrangement position relationship between the target extended partition and the transition partition;

[0011] Expand each of the expansion reference points according to the expansion direction vector, the preset expansion value, and the transition expansion value to obtain a target expansion model.

[0012] Further, the surface of the target model is composed of a plurality of polygon patches spliced together; obtaining the expansion reference points in the target model, and according to the surface shape of the target model, obtaining the expansion direction vector of each of the expansion reference points includes:

[0013] Obtain the vertices of the polygon patch as the expansion reference points;

[0014] According to the expansion reference points, obtain a plurality of associated patches associated with the expansion reference points, and the plurality of associated patches are respectively a plurality of the polygon patches with the expansion reference points as common vertices;

[0015] According to the shape characteristics and spatial position relationship of the plurality of associated patches, obtain the expansion direction vector of the expansion reference point.

[0016] Further, the obtaining the expansion direction vector of the expansion reference point according to the shape characteristics and spatial position relationship of the plurality of associated patches includes:

[0017] Obtain the normal vector of the associated patch;

[0018] Obtain a vector weight according to the shape characteristics of the associated patch, and adjust the normal vector according to the vector weight to obtain a weighted normal vector of the associated patch;

[0019] According to the vector sum of each of the weighted normal vectors, obtain the expansion direction vector of the expansion reference point.

[0020] Further, the obtaining a vector weight according to the shape characteristics of the associated patch, and adjusting the normal vector according to the vector weight to obtain a weighted normal vector of the associated patch includes:

[0021] Obtain the vector weight according to the area of the associated patch;

[0022] Adjust the length of the normal vector according to the vector weight to obtain a weighted normal vector of the associated patch.

[0023] Further, obtaining a preset expansion value for each of the target expansion partitions, and based on the preset expansion value, obtaining a transition expansion value for the transition partition according to the arrangement position relationship between the target expansion partition and the transition partition includes:

[0024] Obtaining a target transition partition and two target expansion partitions adjacent to the target transition partition to obtain a first partition and a second partition;

[0025] According to the preset expansion values of the first partition and the second partition, and the arrangement position relationship between the first partition and the target transition partition, obtaining the transition expansion value of the target transition partition.

[0026] Further, according to the preset expansion values of the first partition and the second partition, and the arrangement position relationship between the first partition and the target transition partition, obtaining the transition expansion value of the target transition partition includes:

[0027] Dividing the target transition region into multiple transition layers along the direction from the first partition to the second partition;

[0028] According to the distance between the transition layer and the first partition, obtaining a distance coefficient of the transition layer;

[0029] According to the preset expansion values of the first partition and the second partition, and based on the distance coefficient, obtaining the transition expansion value of the target transition partition.

[0030] Further, according to the expansion direction vector, the preset expansion value, and the transition expansion value, expanding each expansion reference point to obtain a target expansion model includes:

[0031] Expanding the expansion reference points located within the target expansion partition according to the expansion direction vector and the preset expansion value;

[0032] Expanding the expansion reference points located within the transition partition according to the expansion direction vector and the transition expansion value;

[0033] Smoothing the expanded expansion reference points and obtaining the target expansion model.

[0034] In a second aspect, the present invention further provides a 3D printing external fixation model partition expansion device, including:

[0035] A model import module, configured to obtain a target model, a plurality of target expansion partitions, and a plurality of transition partitions. The plurality of target expansion partitions are arranged on the target model along the material stacking direction of 3D printing, and the plurality of transition partitions are respectively located between two adjacent target expansion partitions;

[0036] A direction analysis module, configured to obtain the external expansion reference points in the target model, and obtain the external expansion direction vectors of each of the external expansion reference points according to the surface shape of the target model;

[0037] An amplitude analysis module, configured to obtain the preset external expansion values of each of the target external expansion partitions, and based on the preset external expansion values, obtain the transition external expansion values of the transition partitions according to the arrangement position relationship between the target external expansion partitions and the transition partitions;

[0038] A model external expansion module, configured to expand each of the external expansion reference points according to the external expansion direction vectors, the preset external expansion values, and the transition external expansion values to obtain a target external expansion model.

[0039] In a third aspect, the present invention further provides an electronic device, including a memory and a processor, wherein,

[0040] The memory is configured to store a program;

[0041] The processor is coupled to the memory and configured to execute the program stored in the memory to implement the steps in the 3D printing external fixation model partition external expansion method in any of the above implementation manners.

[0042] In a fourth aspect, the present invention further provides a computer-readable storage medium, configured to store computer-readable programs or instructions, and when the programs or instructions are executed by a processor, the steps in the 3D printing external fixation model partition external expansion method in any of the above implementation manners can be implemented.

[0043] A 3D printing external fixation model partition external expansion method, device and electronic device provided by the present invention first obtain a target model, a plurality of target external expansion partitions and a plurality of transition partitions, then obtain the external expansion reference points in the target model, and obtain the external expansion direction vectors of each of the external expansion reference points according to the surface shape of the target model, then obtain the preset external expansion values of each of the target external expansion partitions, and based on the preset external expansion values, obtain the transition external expansion values of the transition partitions according to the arrangement position relationship between the target external expansion partitions and the transition partitions, and finally expand each of the external expansion reference points according to the external expansion direction vectors, the preset external expansion values, and the transition external expansion values to obtain a target external expansion model. Compared with the prior art, the present invention realizes the partition external expansion of the 3D printing external fixation model by using the method of expanding the external expansion reference points with the external expansion direction vectors, the preset external expansion values and the transition external expansion values, and because the transition external expansion values are obtained based on the preset external expansion values, in addition to the target external expansion partitions meeting the requirements in the target external expansion model, the external expansion level of the transition partitions also meets the expectations, greatly improving the fitting degree between the model and the patient. Description of the Drawings

[0044] Figure 1 It is a flowchart of a method for a 3D printing external fixation model partition expansion method provided by the present invention;

[0045] Figure 2 is Figure 1 a flowchart of a method for step S102 in an embodiment;

[0046] Figure 3 is Figure 2 a flowchart of a method for step S203 in an embodiment;

[0047] Figure 4 is Figure 1 a flowchart of a method for step S103 in an embodiment;

[0048] Figure 5 It is a schematic structural diagram of a 3D printing external fixation model partition expansion device provided by the present invention;

[0049] Figure 6 It is a schematic structural diagram of an electronic device provided by the present invention. Detailed implementation manners

[0050] Next, the preferred embodiments of the present invention will be specifically described in conjunction with the accompanying drawings. Among them, the accompanying drawings form a part of this application and are used together with the embodiments of the present invention to explain the principles of the present invention, rather than to limit the scope of the present invention.

[0051] In the description of this application, the meaning of "a plurality" is two or more, unless otherwise specifically defined.

[0052] Referring to "embodiment" herein means that a specific feature, structure, or characteristic described in connection with the embodiment may be included in at least one embodiment of the present invention. The phrase appears in various places in the specification and does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment mutually exclusive with other embodiments. Those skilled in the art explicitly and implicitly understand that the embodiments described herein can be combined with other embodiments.

[0053] The present invention obtains the expansion direction vector of each expansion reference point according to the surface shape of the target model, then obtains the transition expansion value of the transition partition according to the partition situation and the preset expansion value, and finally expands the expansion reference points in the target model according to the above data, thereby completing the expansion of the model.

[0054] The present invention provides a 3D printing external fixation model partition expansion method, device, equipment, and storage medium, which will be described separately below.

[0055] Combined with Figure 1As shown in the figure, a specific embodiment of the present invention discloses a method for partitioning and expanding an external fixation model in 3D printing, including:

[0056] S101. Obtain a target model, a plurality of target expansion partitions, and a plurality of transition partitions. The plurality of target expansion partitions are arranged on the target model along the material stacking direction of 3D printing, and the plurality of transition partitions are respectively located between two adjacent target expansion partitions;

[0057] S102. Obtain the expansion reference points in the target model, and according to the surface shape of the target model, obtain the expansion direction vectors of each expansion reference point;

[0058] S103. Obtain the preset expansion value of each target expansion partition, and based on the preset expansion value, obtain the transition expansion value of the transition partition according to the arrangement position relationship between the target expansion partition and the transition partition;

[0059] S104. Expand each expansion reference point according to the expansion direction vector, the preset expansion value, and the transition expansion value to obtain a target expanded model.

[0060] Compared with the prior art, the present invention realizes the partitioning and expansion of the 3D printing external fixation model by using the method of expanding the expansion reference points with the expansion direction vector, the preset expansion value, and the transition expansion value. And because the transition expansion value is obtained based on the preset expansion value, in addition to the target expansion partition meeting the requirements in the target expanded model, the expansion level of the transition partition also meets the expectation, greatly improving the fitting degree between the model and the patient.

[0061] In a preferred embodiment, in step S101 of the above process, the obtained target model is an STL model, and its model surface is composed of a plurality of triangular patches spliced together. It can be understood that in actual implementation, the surface of the target model can also be composed of other polygon patches spliced together, and the type of the target model can also be other types of mesh models.

[0062] Further, in combination with Figure 2 As shown in the figure, in a preferred embodiment, the surface of the target model is composed of a plurality of polygon patches spliced together. The above step S102, obtaining the expansion reference points in the target model, and according to the surface shape of the target model, obtaining the expansion direction vectors of each expansion reference point specifically includes:

[0063] S201. Obtain the vertices of the polygon patch as the expansion reference points;

[0064] S202. Obtain a plurality of associated patches associated with the external expansion reference point. The plurality of associated patches are respectively a plurality of polygon patches with the external expansion reference point as a common vertex.

[0065] S203. Obtain the external expansion direction vector of the external expansion reference point according to the shape features and spatial position relationships of the plurality of associated patches.

[0066] It can be understood that in actual implementation, the selection of the external expansion reference point can be different according to the specific type of the target model. For example, when the target model is a mesh block model, the external expansion reference point can also be the centroid of the mesh block. Similarly, the external expansion direction vector of the external expansion reference point can also be flexibly determined according to the actual situation. For example, when the external expansion reference point is located on the surface of the target model, the direction with the largest gradient around the external expansion reference point can be selected as the external expansion direction vector.

[0067] Further, as shown in Figure 3 In a preferred embodiment, the above step S203. Obtain the external expansion direction vector of the external expansion reference point according to the shape features and spatial position relationships of the plurality of associated patches specifically includes:

[0068] S301. Obtain the normal vector of the associated patch.

[0069] S302. Obtain a vector weight according to the shape feature of the associated patch, and adjust the normal vector according to the vector weight to obtain the weighted normal vector of the associated patch.

[0070] S303. Obtain the external expansion direction vector of the external expansion reference point according to the vector sum of each weighted normal vector.

[0071] In a preferred embodiment, the above step S302. Obtain a vector weight according to the shape feature of the associated patch, and adjust the normal vector according to the vector weight to obtain the weighted normal vector of the associated patch specifically includes:

[0072] Obtain the vector weight according to the area of the associated patch.

[0073] Adjust the length of the normal vector according to the vector weight to obtain the weighted normal vector of the associated patch.

[0074] The above vector weight is obtained according to the area of the associated patch. The larger the area, the larger the weight value. In practice, the vector weight can also be obtained according to other shape features of the associated patch, such as the number of interior angles greater than a set threshold in the associated patch, etc.

[0075] The present invention also provides a more detailed embodiment to more clearly illustrate the above steps S201 - S203:

[0076] First, obtain the normal vector of each triangular patch (i.e., the polygon patch) in the target model (hereinafter referred to as the model), and set P1, P2, P3... P n as the normal vector of the corresponding triangular patch, where n represents the number of triangular patches in the model;

[0077] Then, obtain the area-weighted normal vector of each triangular patch, and the corresponding weighted normal vector ΔP i is:

[0078] ΔP i = P i * S i

[0079] where i represents the serial number of a certain triangular patch, i ∈ [1, n], and S i represents the area of this triangular patch, specifically:

[0080]

[0081] s = (a++) / 2

[0082] where a, b, and c are the lengths of the three sides of the triangular patch respectively, and s is the intermediate coefficient of the operation.

[0083] Then, calculate the vector sum of the weighted normal vectors of the associated patches associated with the outer expansion reference points (i.e., with the outer expansion reference points as vertices) to obtain the normal vector of each outer expansion reference point. Set N1, N2, N3... N m as the outer expansion direction vector of each outer expansion reference point, where m represents the number of outer expansion reference points in the model. There are three associated patches, namely the x, y, and z, associated with the j-th outer expansion reference point, x, y, z ∈ [1, n], j ∈ [1, m], then:

[0084] N j = ΔP x + ΔP y + ΔP z

[0085] Furthermore, as shown in Figure 4 In a preferred embodiment, the above step S103, obtain the preset outer expansion value of each target outer expansion partition, and based on the preset outer expansion value, according to the arrangement position relationship between the target outer expansion partition and the transition partition, obtain the transition outer expansion value of the transition partition, specifically including:

[0086] S401. Obtain the target transition partition and two target outer expansion partitions adjacent to the target transition partition to obtain the first partition and the second partition;

[0087] S402. Obtain the transition expansion value of the target transition partition according to the preset expansion values of the first partition and the second partition, and the arrangement position relationship between the first partition and the target transition partition.

[0088] Specifically, in a preferred embodiment, the above step S402, obtaining the transition expansion value of the target transition partition according to the preset expansion values of the first partition and the second partition, and the arrangement position relationship between the first partition and the target transition partition, specifically includes:

[0089] Divide the target transition area into multiple transition layers along the direction from the first partition to the second partition;

[0090] Obtain the distance coefficient of the transition layer according to the distance between the transition layer and the first partition;

[0091] Based on the preset expansion values of the first partition and the second partition, and based on the distance coefficient, obtain the transition expansion value of the target transition partition.

[0092] Based on the above method, in the finally expanded model, the transition between the two partitions is smoother, making the model more fitting.

[0093] The present invention also provides a more detailed embodiment to more clearly illustrate the above steps S401 - S402:

[0094] In this embodiment, divide the transition partition into two layers along the arrangement direction of the target expansion partition (in practice, it can also be divided into multiple layers according to needs, such as four layers, five layers, etc.), and then set two transition expansion values for the two transition layers to achieve a better transition effect. Let the preset expansion value of the target expansion partition (i.e., the first partition) on one side of the transition partition be q1, and the preset expansion value of the other target expansion partition (i.e., the second partition) on the other side be q4 (both q1 and q4 are specified manually according to the actual situation of the patient), and the transition expansion values of the two transition layers are q2 and q3 respectively, where:

[0095] q2 = q1 + 0.333 * (q4 - q1)

[0096] q3 = q1 + 0.667 * (q4 - q1)

[0097] The 0.333 and 0.667 in the formula are parameters that can reflect the distance between the transition layer and the first partition, that is, the distance coefficient. In practice, its specific value can be specified manually according to relevant rules.

[0098] In addition, it can be understood that in practice, the above-mentioned preset outward expansion value and transitional outward expansion value can also be negative numbers, that is, the target model shrinks inward. The specific process in the case of shrinkage is the same as described in this article, and those skilled in the art can think of it according to the description in this article, so no further elaboration will be made.

[0099] Further, in a preferred embodiment, the above step S104, according to the outward expansion direction vector, the preset outward expansion value and the transitional outward expansion value, expand each of the outward expansion reference points to obtain a target outward expansion model, specifically includes:

[0100] Expand the outward expansion reference points located within the target outward expansion partition according to the outward expansion direction vector and the preset outward expansion value;

[0101] Expand the outward expansion reference points located within the transitional partition according to the outward expansion direction vector and the transitional outward expansion value;

[0102] Smooth the expanded outward expansion reference points to obtain the target outward expansion model.

[0103] The present invention also provides a more detailed embodiment to more clearly illustrate the above step S104:

[0104] First, determine the area where the outward expansion reference point is located, and then move the point along the outward expansion direction vector according to the preset outward expansion value or transitional outward expansion value corresponding to each outward expansion reference point. In this embodiment, the initial coordinate of the j-th outward expansion reference point is O, and the area where it is located is the above-mentioned first partition, then the expanded coordinate O' is:

[0105] O' = O + O * N j * q1, j ∈ [1, m]

[0106] Then smooth the model after partition expansion to improve the quality of the mesh and the model, and obtain the final target outward expansion model.

[0107] To better implement the 3D printing external fixation model partition expansion method in the embodiments of the present invention, on the basis of the 3D printing external fixation model partition expansion method, correspondingly, please refer to Figure 5 , Figure 5 is a schematic structural diagram of an embodiment of a 3D printing external fixation model partition expansion device provided by the present invention. A 3D printing external fixation model partition expansion device 500 provided by an embodiment of the present invention includes:

[0108] A model import module 510, configured to obtain a target model, a plurality of target outward expansion partitions and a plurality of transitional partitions. The plurality of target outward expansion partitions are arranged on the target model along the material stacking direction of 3D printing, and the plurality of transitional partitions are respectively located between two adjacent target outward expansion partitions;

[0109] A direction analysis module 520, configured to obtain the extended reference points in the target model, and obtain the extended direction vectors of each of the extended reference points according to the surface shape of the target model;

[0110] An amplitude analysis module 530, configured to obtain the preset extension value of each of the target extended partitions, and based on the preset extension value, obtain the transition extension value of the transition partition according to the arrangement position relationship between the target extended partition and the transition partition;

[0111] A model extension module 540, configured to extend each of the extended reference points according to the extended direction vector, the preset extension value, and the transition extension value, to obtain a target extended model.

[0112] It should be noted here that: the corresponding device 500 provided in the above embodiment can implement the technical solutions described in the above method embodiments. The specific implementation principles of the above modules or units can refer to the corresponding content in the above method embodiments, which will not be elaborated here.

[0113] Please refer to Figure 6 , Figure 6 which is a schematic structural diagram of an electronic device provided in an embodiment of the present invention. Based on the above 3D printing external fixation model partition extension method, the present invention also correspondingly provides a 3D printing external fixation model partition extension device 600, that is, the above electronic device. The 3D printing external fixation model partition extension device 600 may be a computing device such as a mobile terminal, a desktop computer, a notebook, a palm computer, and a server. The 3D printing external fixation model partition extension device 600 includes a processor 610, a memory 620, and a display 630. Figure 6 Only some components of the 3D printing external fixation model partition extension device are shown, but it should be understood that it is not required to implement all the shown components, and more or fewer components can be alternatively implemented.

[0114] The memory 620 may be an internal storage unit of the 3D printing external fixation model partition expansion device 600 in some embodiments, such as the hard disk or memory of the 3D printing external fixation model partition expansion device 600. The memory 620 may also be an external storage device of the 3D printing external fixation model partition expansion device 600 in other embodiments, such as a plug-in hard disk, a Smart Media Card (SMC), a Secure Digital (SD) card, a Flash Card, etc. equipped on the 3D printing external fixation model partition expansion device 600. Further, the memory 620 may also include both the internal storage unit and the external storage device of the 3D printing external fixation model partition expansion device 600. The memory 620 is used to store application software and various types of data installed on the 3D printing external fixation model partition expansion device 600, such as program codes installed on the 3D printing external fixation model partition expansion device 600, etc. The memory 620 may also be used to temporarily store data that has been output or will be output. In one embodiment, a 3D printing external fixation model partition expansion program 640 is stored on the memory 620, and the 3D printing external fixation model partition expansion program 640 can be executed by the processor 610, so as to implement the 3D printing external fixation model partition expansion method of each embodiment of the present application.

[0115] The processor 610 may be a central processing unit (CPU), a microprocessor or other data processing chips in some embodiments, and is used to run program codes stored in the memory 620 or process data, such as executing the 3D printing external fixation model partition expansion method, etc.

[0116] The display 630 may be an LED display, a liquid crystal display, a touch liquid crystal display, an OLED (Organic Light-Emitting Diode) toucher, etc. in some embodiments. The display 630 is used to display information on the 3D printing external fixation model partition expansion device 600 and to display a visual user interface. The components 610-630 of the 3D printing external fixation model partition expansion device 600 communicate with each other through a system bus.

[0117] In one embodiment, when the processor 610 executes the 3D printing external fixation model partition expansion program 640 in the memory 620, the steps in the above 3D printing external fixation model partition expansion method are implemented.

[0118] This embodiment also provides a computer-readable storage medium, on which a 3D printing external fixation model partition expansion program is stored, and when the 3D printing external fixation model partition expansion program is executed by a processor, the steps in the above embodiments can be implemented.

[0119] A method, device and electronic device for partitioned outward expansion of a 3D printing external fixation model provided by the present invention first obtain a target model, a plurality of target outward expansion partitions and a plurality of transition partitions, then obtain outward expansion reference points in the target model, and obtain an outward expansion direction vector for each of the outward expansion reference points according to the surface shape of the target model. Then, a preset outward expansion value for each of the target outward expansion partitions is obtained, and based on the preset outward expansion value, a transition outward expansion value for the transition partition is obtained according to the arrangement position relationship between the target outward expansion partition and the transition partition. Finally, each of the outward expansion reference points is outwardly expanded according to the outward expansion direction vector, the preset outward expansion value and the transition outward expansion value to obtain a target outward expansion model. Compared with the prior art, the present invention realizes the partitioned outward expansion of the 3D printing external fixation model by using the outward expansion direction vector, the preset outward expansion value and the transition outward expansion value to expand the outward expansion reference points. And because the transition outward expansion value is obtained based on the preset outward expansion value, in addition to the target outward expansion partition meeting the requirements in the target outward expansion model, the outward expansion level of the transition partition also meets the expectation, greatly improving the fitting degree between the model and the patient.

[0120] The above is only a preferred specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by those skilled in the art within the technical scope disclosed by the present invention should be covered by the protection scope of the present invention.

Claims

1. A method for partitioning and expanding a 3D printed external fixation model, characterized in that, Including: Obtaining a target model, a plurality of target outer expansion partitions, and a plurality of transition partitions. The plurality of target outer expansion partitions are arranged on the target model along the material stacking direction of 3D printing, and the plurality of transition partitions are respectively located between two adjacent target outer expansion partitions; Obtaining outer expansion reference points in the target model, and obtaining an outer expansion direction vector for each outer expansion reference point according to the surface shape of the target model; Obtaining a preset outer expansion value for each target outer expansion partition, and based on the preset outer expansion value, obtaining a transition outer expansion value for the transition partition according to the arrangement position relationship between the target outer expansion partition and the transition partition; Expanding each outer expansion reference point according to the outer expansion direction vector, the preset outer expansion value, and the transition outer expansion value to obtain a target outer expansion model; The obtaining a preset outer expansion value for each target outer expansion partition, and based on the preset outer expansion value, obtaining a transition outer expansion value for the transition partition according to the arrangement position relationship between the target outer expansion partition and the transition partition includes: Obtaining a target transition partition and two target outer expansion partitions adjacent to the target transition partition to obtain a first partition and a second partition; Obtaining the transition outer expansion value of the target transition partition according to the preset outer expansion values of the first partition and the second partition, and the arrangement position relationship between the first partition and the target transition partition; The obtaining the transition outer expansion value of the target transition partition according to the preset outer expansion values of the first partition and the second partition, and the arrangement position relationship between the first partition and the target transition partition includes: Dividing the target transition partition into a plurality of transition layers along the direction from the first partition to the second partition; Obtaining a distance coefficient for the transition layer according to the distance between the transition layer and the first partition; Obtaining the transition outer expansion value of the target transition partition based on the distance coefficient according to the preset outer expansion values of the first partition and the second partition; The obtaining the transition outer expansion value of the target transition partition based on the distance coefficient according to the preset outer expansion values of the first partition and the second partition includes: Calculating the difference between the preset outer expansion values of the second partition and the first partition, calculating the product result of the difference and the distance coefficient, and adding the product result to the preset outer expansion value of the first partition to obtain the transition outer expansion value of the target transition partition.

2. The 3D printing external fixation model partition and external expansion method according to claim 1, characterized in that The surface of the target model is composed of a plurality of polygon patches spliced together; the obtaining outer expansion reference points in the target model, and obtaining an outer expansion direction vector for each outer expansion reference point according to the surface shape of the target model includes: Obtaining the vertices of the polygon patches as the outer expansion reference points; Obtaining a plurality of associated patches associated with the outer expansion reference point according to the outer expansion reference point, and the plurality of associated patches are respectively a plurality of polygon patches with the outer expansion reference point as a common vertex; Obtaining the outer expansion direction vector of the outer expansion reference point according to the shape characteristics and spatial position relationships of the plurality of associated patches.

3. The 3D printing external fixation model partition and external expansion method according to claim 2, characterized in that Obtaining the outward expansion direction vector of the outward expansion reference point according to the shape features and spatial position relationships of the multiple associated patches includes: Obtaining the normal vectors of the associated patches; Obtaining vector weights according to the shape features of the associated patches, and adjusting the normal vectors according to the vector weights to obtain the weighted normal vectors of the associated patches; Obtaining the outward expansion direction vector of the outward expansion reference point according to the vector sum of each of the weighted normal vectors.

4. The 3D printing external fixation model partition external expansion method according to claim 3, characterized in that, The obtaining vector weights according to the shape features of the associated patches, and adjusting the normal vectors according to the vector weights to obtain the weighted normal vectors of the associated patches includes: Obtaining the vector weights according to the areas of the associated patches; Adjusting the lengths of the normal vectors according to the vector weights to obtain the weighted normal vectors of the associated patches.

5. The 3D printing external fixation model partitioned outward expansion method according to claim 1, wherein Outwardly expanding each of the outward expansion reference points according to the outward expansion direction vector, the preset outward expansion value, and the transitional outward expansion value to obtain a target outward expansion model includes: Outwardly expanding the outward expansion reference points located within the target outward expansion partition according to the outward expansion direction vector and the preset outward expansion value; Outwardly expanding the outward expansion reference points located within the transitional partition according to the outward expansion direction vector and the transitional outward expansion value; Smoothing the outwardly expanded outward expansion reference points to obtain the target outward expansion model.

6. A 3D printing external fixation model partitioned external expansion device, characterized in that, Including: A model import module, configured to obtain a target model, multiple target outward expansion partitions, and multiple transitional partitions, where the multiple target outward expansion partitions are arranged on the target model along the material stacking direction of 3D printing, and the multiple transitional partitions are respectively located between two adjacent target outward expansion partitions; A direction analysis module, configured to obtain the outward expansion reference points in the target model, and obtain the outward expansion direction vector of each of the outward expansion reference points according to the surface shape of the target model; An amplitude analysis module, configured to obtain the preset outward expansion value of each target outward expansion partition, and based on the preset outward expansion value, obtain the transitional outward expansion value of the transitional partition according to the arrangement position relationship between the target outward expansion partition and the transitional partition; A model outward expansion module, configured to outwardly expand each of the outward expansion reference points according to the outward expansion direction vector, the preset outward expansion value, and the transitional outward expansion value to obtain a target outward expansion model; The obtaining the preset outward expansion value of each target outward expansion partition, and based on the preset outward expansion value, obtaining the transitional outward expansion value of the transitional partition according to the arrangement position relationship between the target outward expansion partition and the transitional partition includes: Obtaining a target transitional partition and two target outward expansion partitions adjacent to the target transitional partition to obtain a first partition and a second partition; Obtaining the transitional outward expansion value of the target transitional partition according to the preset outward expansion values of the first partition and the second partition, and the arrangement position relationship between the first partition and the target transitional partition; The obtaining the transitional outward expansion value of the target transitional partition according to the preset outward expansion values of the first partition and the second partition, and the arrangement position relationship between the first partition and the target transitional partition includes: Divide the target transition partition into multiple transition layers along the direction from the first partition to the second partition; Obtain the distance coefficient of the transition layer according to the distance between the transition layer and the first partition; Based on the distance coefficient, obtain the transition expansion value of the target transition partition according to the preset expansion values of the first partition and the second partition; The obtaining the transition expansion value of the target transition partition based on the distance coefficient according to the preset expansion values of the first partition and the second partition includes: Calculate the difference between the preset expansion values of the second partition and the first partition, calculate the product result of the difference and the distance coefficient, and add the product result to the preset expansion value of the first partition to obtain the transition expansion value of the target transition partition.

7. An electronic device, characterized in that, It includes a memory and a processor, wherein, The memory is used to store programs; The processor is coupled to the memory and is used to execute the program stored in the memory to implement the steps in the 3D printing external fixation model partition expansion method described in any one of claims 1 to 5 above.

8. A computer-readable storage medium, characterized in that, For storing computer-readable programs or instructions, when the programs or instructions are executed by a processor, the steps in the 3D printing external fixation model partition expansion method described in any one of claims 1 to 5 above can be implemented.

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