Minimum curved surface bone scaffold wall thickness optimization method based on stress guidance

Abstract

The invention relates to the technical field of minimum-curved-surface bone scaffold wall thickness optimization, in particular to a minimum-curved-surface bone scaffold wall thickness optimization method based on stress guidance. The method comprises the following steps: constructing a Gyandroid support model with a Sheet configuration on the basis of a Gyandroid implicit equation in a three-period minimal curved surface, and constructing a Diamond support model with the Sheet configuration on the basis of a Diamond implicit equation in the three-period minimal curved surface; performing mechanical compression simulation on the Gyandroid support model to determine a high stress area of the Gyandroid support model, and performing mechanical compression simulation on the Diamond support model to determine a high stress area of the Diamond support model; and determining a stress rule based on the high-stress area of the Gyandroid support model, and marking the high-stress area in the Gyandroid support model through the stress rule to obtain a high-stress marked area of the Gyandroid support model. In this way, the problem of contradiction between compressive strength and biomechanical matching performance can be effectively solved, and excellent biological performance is achieved.

Description

Technical Field

[0001] This invention relates to the field of wall thickness optimization technology for minimally curved bone scaffolds, and specifically to a stress-guided method for optimizing the wall thickness of minimally curved bone scaffolds. Background Technology

[0002] Bones are vital to human life and health, playing a crucial role in supporting the body and enabling movement. Bone defects can occur due to congenital defects, sports injuries, accidents, bone tumor surgery, and joint replacement revisions. A common treatment for bone defects is repair through the implantation of bone scaffolds. These scaffolds are synthesized using artificially synthesized biomaterials to achieve better bone formation, osteoconduction, and bone induction. They can continuously fill the removed gaps, provide efficient load transfer, and allow for intraosseous growth and angiogenesis, demonstrating immense potential for future development.

[0003] Triply Periodic Minimal Surface (TPMS) structures have become ideal filling structures for porous bone scaffolds due to their excellent biomimetic properties and large specific surface area, which can improve the bone repair effect.

[0004] Porous bone scaffolds primarily serve a supporting function after implantation; therefore, their compressive strength must meet the weight-bearing requirements of the bone while avoiding stress shielding due to excessive elastic modulus after implantation. Porosity is a crucial factor affecting the mechanical properties of bone scaffolds. Reducing porosity can increase compressive strength, but it also increases the elastic modulus. In other words, good compressive strength implies an excessively high elastic modulus. Therefore, the relationship between compressive strength and elastic modulus makes designing porous scaffolds with high load-bearing strength and high biomechanical compatibility a challenge. Summary of the Invention

[0005] The purpose of this invention is to provide a stress-guided method for optimizing the wall thickness of a minimal surface bone scaffold. By studying the load response of the structure in compression simulation and optimizing the structure according to the law presented by the load response, the compressive strength and biomechanical compatibility are improved while ensuring the basic topological structure of the triple-period minimal surface.

[0006] In an embodiment of the present invention, a stress-guided method for optimizing the wall thickness of a minimal curved surface bone scaffold is provided, comprising:

[0007] Step 101. Construct a Gyroid scaffold model with a Sheet configuration based on the Gyroid-type implicit equations in the three-period minimal surface, and simultaneously construct a Diamond scaffold model with a Sheet configuration based on the Diamond-type implicit equations in the three-period minimal surface.

[0008] Step 102. Perform mechanical compression simulation on the Gyroid scaffold model to determine the high stress region of the Gyroid scaffold model, and at the same time perform mechanical compression simulation on the Diamond scaffold model to determine the high stress region of the Diamond scaffold model.

[0009] Step 103. Determine the stress law based on the high stress region of the Gyroid scaffold model, and mark the high stress region in the Gyroid scaffold model according to the stress law to obtain the high stress marked region of the Gyroid scaffold model; at the same time, determine the stress law based on the high stress region of the Diamond scaffold model, and mark the high stress region in the Diamond scaffold model according to the stress law to obtain the high stress marked region of the Diamond scaffold model.

[0010] Step 104. Smoothly thicken the high-stress marked area of ​​the Gyroid scaffold model to obtain the optimized Gyroid scaffold model, and smoothly thicken the high-stress marked area of ​​the Diamond scaffold model to obtain the optimized Diamond scaffold model.

[0011] Step 105. Perform mechanical compression simulation on the optimized Gyroid scaffold model to determine the optimization effect, and simultaneously perform mechanical compression simulation on the optimized Diamond scaffold model to determine the optimization effect.

[0012] As a preferred embodiment of the present invention, in step 101, the Gyroid-type implicit equations in the Gyroid scaffold model with a Sheet configuration, constructed based on the Gyroid-type implicit equations in the three-period minimal surface, are as follows: .

[0013] Where L represents the unit cell size, and C is the bias function used to adjust the Gyroid-type implicit equation.

[0014] As a preferred embodiment of the present invention, in step 101, the Diamond-type implicit equations in the Diamond-type implicit equations constructed based on the Diamond-type implicit equations in the three-period minimal surface are as follows: .

[0015] Where L represents the unit cell size, and C is the bias function used to adjust the Diamond-type implicit equation.

[0016] As a preferred embodiment of the present invention, step 102, performing mechanical compression simulation on the Gyroid scaffold model to determine the high-stress region of the Gyroid scaffold model, includes:

[0017] The Gyroid scaffold model was imported into 3-matic software in .stl format for two-dimensional and three-dimensional mesh generation. The meshed Gyroid scaffold model was then imported into the Abaqus platform in .inp format for mechanical compression simulation to obtain the stress cloud map of the Gyroid scaffold model. The high-stress areas of the Gyroid scaffold model were determined through the stress cloud map.

[0018] As a preferred embodiment of the present invention, step 102, performing mechanical compression simulation on the Diamond support model to determine the high-stress region of the Diamond support model, includes:

[0019] The Diamond support model was imported into 3-matic software in .stl format for two-dimensional and three-dimensional mesh generation. The meshed Diamond support model was then imported into the Abaqus platform in .inp format for mechanical compression simulation to obtain the stress cloud map of the Diamond support model. The high-stress areas of the Diamond support model were determined through the stress cloud map.

[0020] As a preferred embodiment of the present invention, in step 103, marking the high-stress areas in the Gyroid scaffold model based on stress patterns to obtain the high-stress marked areas of the Gyroid scaffold model specifically involves:

[0021] The high-stress regions in the Gyroid scaffold model were marked using Mathematica software and the angle between the gradient direction and the compression direction in the mathematical expression of the Gyroid scaffold model. The angle between the gradient direction and the compression direction in the mathematical expression of the Gyroid scaffold model satisfies the following formula: .

[0022] in, For the mathematical expression of the Gyroid scaffold model; This represents the angle between the gradient direction and the compression direction in the mathematical expression of the Gyroid scaffold model. This represents the minimum angle between the gradient direction and the compression direction in the mathematical expression of the Gyroid scaffold model. This represents the maximum angle between the gradient direction and the compression direction in the mathematical expression of the Gyroid scaffold model.

[0023] As a preferred embodiment of the present invention, in step 103, marking the high-stress areas in the Diamond support model based on stress patterns to obtain the high-stress marked areas of the Diamond support model specifically involves:

[0024] The high-stress regions in the Diamond scaffold model were marked using Mathematica software and the angle between the gradient direction and the compression direction in the mathematical expression of the Diamond scaffold model. The angle between the gradient direction and the compression direction in the mathematical expression of the Diamond scaffold model satisfies the following formula: .

[0025] in, The mathematical expression for the Diamond scaffold model; This represents the angle between the gradient direction and the compression direction in the mathematical expression of the Diamond scaffold model. This represents the minimum angle between the gradient direction and the compression direction in the mathematical expression of the Diamond scaffold model. This represents the maximum angle between the gradient direction and the compression direction in the mathematical expression of the Diamond scaffold model.

[0026] As a preferred embodiment of the present invention, in step 104, the high-stress marked area of ​​the Gyroid scaffold model is thickened with a smooth transition to obtain the optimized Gyroid scaffold model, specifically as follows:

[0027] Using Mathematica software and based on the parametric control equations, the curve with a 90° angle between the gradient direction and the compression direction in the mathematical expression of the Gyroid scaffold model was extracted. The parametric control equations are as follows: .

[0028] in, For the mathematical expression of the Gyroid scaffold model; This represents the angle between the gradient direction and the compression direction in the mathematical expression of the Gyroid scaffold model.

[0029] The high-stress areas and curves in the Gyroid scaffold model obtained from Mathematica software were imported into Solidworks software for modeling to obtain an optimized Gyroid scaffold model.

[0030] As a preferred embodiment of the present invention, in step 104, the high-stress marked area of ​​the Diamond support model is thickened with a smooth transition to obtain the optimized Diamond support model, specifically as follows:

[0031] Using Mathematica software and based on the parametric control equations, the curve with a 90° angle between the gradient direction and the compression direction in the mathematical expression of the Diamond scaffold model was extracted. The parametric control equations are as follows: .

[0032] in, The mathematical expression for the Diamond scaffold model; This represents the angle between the gradient direction and the compression direction in the mathematical expression of the Diamond scaffold model.

[0033] The high-stress areas and curves in the Diamond scaffold model obtained from Mathematica software were imported into Solidworks software for modeling to obtain an optimized Diamond scaffold model.

[0034] As a preferred embodiment of the present invention, step 105, performing mechanical compression simulation on the optimized Gyroid scaffold model to determine the optimization effect includes:

[0035] The optimized Gyroid scaffold model was imported into 3-matic software in .stl format for two-dimensional and three-dimensional mesh generation. The optimized Gyroid scaffold model after mesh generation was then imported into the Abaqus platform in .inp format for mechanical compression simulation. The stress-strain curves of the optimized Gyroid scaffold model were exported. Based on the stress-strain curves, the yield strength and elastic modulus of the optimized Gyroid scaffold model were calculated. The optimization effect of the Gyroid scaffold model was determined based on the yield strength and elastic modulus of the optimized Gyroid scaffold model.

[0036] Mechanical compression simulations were performed on the optimized Diamond scaffold model to determine the optimization effect, including:

[0037] The optimized Diamond support model was imported into 3-matic software in .stl format for two-dimensional and three-dimensional mesh generation. The optimized Diamond support model after mesh generation was then imported into the Abaqus platform in .inp format for mechanical compression simulation. The stress-strain curves of the optimized Diamond support model were exported. Based on the stress-strain curves, the yield strength and elastic modulus of the optimized Diamond support model were calculated. The optimization effect of the Diamond support model was determined based on the yield strength and elastic modulus of the optimized Diamond support model.

[0038] In summary, the present invention has the following beneficial effects:

[0039] The method of this invention first constructs a Gyroid scaffold model and a Diamond scaffold model. Then, mechanical compression simulations are performed on the Gyroid and Diamond scaffold models respectively to identify high-stress regions. Next, the high-stress regions of the Gyroid and Diamond scaffold models are marked. Then, the marked high-stress regions of the Gyroid and Diamond scaffold models are thickened with a smooth transition to obtain optimized Gyroid and Diamond scaffold models. Finally, mechanical compression simulations are performed on the optimized Gyroid and Diamond scaffold models to determine the optimization effect. The optimization effect shows that, under the same porosity, the compressive strength of the optimized Gyroid and Diamond scaffold models is higher than that of the initial Gyroid and Diamond scaffold models, and the increase in elastic modulus is not significant (both are within the elastic modulus range of natural cortical bone). Therefore, the stress-guided minimal curved surface bone scaffold wall thickness optimization method of this invention can effectively solve the contradiction between compressive strength and biomechanical matching, and has excellent biological performance.

[0040] Further or more detailed beneficial effects will be described in conjunction with specific embodiments in the detailed implementation. Attached Figure Description

[0041] Figure 1 The stress cloud diagram of the Gyroid scaffold model according to an embodiment of the present invention is shown;

[0042] Figure 2 The stress cloud diagram of the Diamond scaffold model according to an embodiment of the present invention is shown;

[0043] Figure 3 This diagram illustrates the marking of high-stress areas in a Gyroid scaffold model according to an embodiment of the present invention.

[0044] Figure 4 This diagram illustrates the marking of high-stress areas in a Diamond scaffold model according to an embodiment of the present invention.

[0045] Figure 5 This diagram illustrates the connection of the ribbon-like spiral region in the Gyroid scaffold model according to an embodiment of the present invention.

[0046] Figure 6 This diagram illustrates the connection of the ribbon-like spiral region in the Diamond scaffold model according to an embodiment of the present invention.

[0047] Figure 7The diagram shows a front view of a curve in the mathematical expression of the Gyroid scaffold model according to an embodiment of the present invention, where the angle between the gradient direction and the compression direction is 90°.

[0048] Figure 8 It shows Figure 7 Top view of the curve;

[0049] Figure 9 The diagram shows a front view of a curve in the mathematical expression of the Diamond scaffold model according to an embodiment of the present invention, where the angle between the gradient direction and the compression direction is 90°.

[0050] Figure 10 It shows Figure 9 Top view of the curve;

[0051] Figure 11 A schematic diagram of the optimized Gyroid scaffold model according to an embodiment of the present invention is shown;

[0052] Figure 12 A schematic diagram of the optimized Diamond scaffold model according to an embodiment of the present invention is shown;

[0053] Figure 13 Schematic diagrams of three optimized Gyroid scaffold models according to embodiments of the present invention are shown;

[0054] Figure 14 Schematic diagrams of three optimized Diamond scaffold models according to embodiments of the present invention are shown;

[0055] Figure 15 A schematic diagram of the stress-strain curves of three optimized Gyroid scaffold models according to an embodiment of the present invention is shown.

[0056] Figure 16 The diagram shows the stress-strain curves of three optimized Diamond scaffold models according to embodiments of the present invention. Detailed Implementation

[0057] Embodiments of the present invention will now be described in more detail with reference to the accompanying drawings. While some embodiments of the invention are shown in the drawings, it should be understood that the invention can be implemented in various forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided to provide a more thorough and complete understanding of the invention. It should be understood that the accompanying drawings and embodiments are for illustrative purposes only and are not intended to limit the scope of protection of the invention.

[0058] In the description of embodiments of the present invention, the term "comprising" and similar terms should be understood as open-ended inclusion, i.e., "including but not limited to". The term "based on" should be understood as "at least partially based on". The term "one embodiment" or "the embodiment" should be understood as "at least one embodiment". The terms "first", "second", etc., may refer to different or the same objects. Other explicit and implicit definitions may also be included below.

[0059] This invention proposes a stress-guided method for optimizing the wall thickness of a minimal curved surface bone scaffold, comprising:

[0060] Step 101. Construct a Gyroid scaffold model with a Sheet configuration based on the Gyroid-type implicit equations in the three-period minimal surface, and simultaneously construct a Diamond scaffold model with a Sheet configuration based on the Diamond-type implicit equations in the three-period minimal surface.

[0061] In this embodiment, the Gyroid-type implicit equations in the Gyroid scaffold model with a Sheet configuration, constructed based on the Gyroid-type implicit equations in the three-period minimal surface, are as follows:

[0062]

[0063] Here, L represents the unit cell size, and C is the bias function used to adjust the implicit equation of the Gyroid type. Controlling the values ​​of L and C allows for precise control of the porosity of the Gyroid scaffold model. To ensure the Gyroid scaffold model meets printability and good permeability requirements, L is set to 3. Simultaneously, the value of C in the implicit equation of the Gyroid type can be adjusted to achieve a porosity of 70% for the Gyroid scaffold model, with a size of 9×9×9 mm.

[0064] The Diamond-type implicit equations in the Diamond-type implicit equations constructed based on the three-period minimum surface are as follows: .

[0065] Here, L represents the unit cell size, and C is the bias function used to adjust the implicit equation of the Diamond type. Controlling the values ​​of L and C allows for precise control of the porosity of the Diamond scaffold model. To ensure printability and good permeability, L is set to 3. Simultaneously, the value of C in the implicit equation of the Diamond type can be adjusted to achieve a porosity of 70% for the Diamond scaffold model, with a size of 9×9×9 mm.

[0066] In the modeling software Mathematica, by solving the aforementioned implicit equations of the Gyroid or Diamond type and setting a non-zero C value (making the porosity of the Gyroid or Diamond scaffold model 70%), a Gyroid Sheet structure or Diamond Sheet structure with solid thickness can be generated. Then, this infinitely extending Gyroid Sheet or Diamond Sheet structure is periodically trimmed in the x, y, and z directions, confining it to a specific volume (e.g., a 9×9×9 mm³ cube space), resulting in a solid Gyroid scaffold model or Diamond scaffold model suitable for 3D printing.

[0067] Step 102. Perform mechanical compression simulation on the Gyroid scaffold model to determine the high-stress areas of the Gyroid scaffold model, and simultaneously perform mechanical compression simulation on the Diamond scaffold model to determine the high-stress areas of the Diamond scaffold model.

[0068] In this embodiment, mechanical compression simulation of the Gyroid scaffold model is performed to determine the high-stress areas of the Gyroid scaffold model, including:

[0069] The Gyroid scaffold model was imported into 3-matic software in .stl format for 2D and 3D mesh generation. The meshed Gyroid scaffold model was then imported into the Abaqus platform in .inp format for mechanical compression simulation to obtain the stress contour plot of the Gyroid scaffold model (see reference). Figure 1 As shown in the figure, the high-stress areas of the Gyroid scaffold model are determined by stress cloud diagram of the Gyroid scaffold model.

[0070] Mechanical compression simulations were performed on the Diamond scaffold model to determine the high-stress regions, including:

[0071] The Diamond support model was imported into 3-matic software in .stl format for 2D and 3D mesh generation. The meshed Diamond support model was then imported into the Abaqus platform in .inp format for mechanical compression simulation to obtain the stress contour plot of the Diamond support model (see reference). Figure 2 As shown in the figure, the high-stress areas of the Diamond support model are determined by stress cloud diagram of the Diamond support model.

[0072] Step 103. Determine the stress law based on the high-stress region of the Gyroid scaffold model, and mark the high-stress region in the Gyroid scaffold model according to the stress law to obtain the high-stress marked region of the Gyroid scaffold model; at the same time, determine the stress law based on the high-stress region of the Diamond scaffold model, and mark the high-stress region in the Diamond scaffold model according to the stress law to obtain the high-stress marked region of the Diamond scaffold model.

[0073] In this embodiment, the high-stress areas in the Gyroid scaffold model are marked according to the stress law (the high-stress areas in the Gyroid scaffold model exhibit a spiral band shape) to obtain the specific high-stress marked areas of the Gyroid scaffold model:

[0074] High-stress regions in the Gyroid scaffold model were marked using Mathematica software and the angle between the gradient direction and the compression direction (i.e., the Z-axis direction) in the mathematical expression of the Gyroid scaffold model (see reference). Figure 3 As shown), and the angle between the gradient direction and the compression direction in the mathematical expression of the Gyroid scaffold model satisfies the following formula: .

[0075] in, For the mathematical expression of the Gyroid scaffold model; This represents the angle between the gradient direction and the compression direction in the mathematical expression of the Gyroid scaffold model. This represents the minimum angle between the gradient direction and the compression direction in the mathematical expression of the Gyroid scaffold model. This represents the maximum angle between the gradient direction and the compression direction in the mathematical expression of the Gyroid scaffold model.

[0076] In this embodiment, the high-stress areas in the Diamond scaffold model are marked according to the stress law (the high-stress areas in the Diamond scaffold model exhibit a spiral band shape) to obtain the specific high-stress marked areas of the Diamond scaffold model:

[0077] Using Mathematica software and the angle between the gradient direction and the compression direction (i.e., the Z-axis direction) in the mathematical expression of the Diamond scaffold model, high-stress areas in the Diamond scaffold model were marked (refer to...). Figure 4 As shown), and the angle between the gradient direction and the compression direction in the mathematical expression of the Diamond scaffold model satisfies the following formula: .

[0078] in, The mathematical expression for the Diamond scaffold model; This represents the angle between the gradient direction and the compression direction in the mathematical expression of the Diamond scaffold model. This represents the minimum angle between the gradient direction and the compression direction in the mathematical expression of the Diamond scaffold model. This represents the maximum angle between the gradient direction and the compression direction in the mathematical expression of the Diamond scaffold model.

[0079] This embodiment uses an included angle range to represent the boundary of the region to be optimized. Compression simulations are performed within different included angle ranges. Analysis reveals that the difference between the maximum and minimum included angle values ​​must not exceed 65°; otherwise, the ribbon-like spiral region of the Gyroid scaffold model will show connections (see [reference]). Figure 5 As shown) and the ribbon-like spiral region of the Diamond scaffold model will show connections (see...). Figure 6 As shown in the figure, wall thickness cannot be optimized through numerical methods.

[0080] Step 104. Smoothly thicken the high-stress marked area of ​​the Gyroid scaffold model to obtain the optimized Gyroid scaffold model, and smoothly thicken the high-stress marked area of ​​the Diamond scaffold model to obtain the optimized Diamond scaffold model.

[0081] In this embodiment, the high-stress marked area of ​​the Gyroid scaffold model is smoothly thickened (the maximum thickening factor is twice, and the porosity of the thickened Gyroid scaffold model is controlled at 70%) to obtain the optimized Gyroid scaffold model.

[0082] Using Mathematica software and based on parametric control equations, a curve with a 90° angle between the gradient direction and the compression direction was extracted from the mathematical expression of the Gyroid scaffold model (see reference). Figure 7 and Figure 8 As shown), the parameter control equations are: .

[0083] in, For the mathematical expression of the Gyroid scaffold model; This represents the angle between the gradient direction and the compression direction in the mathematical expression of the Gyroid scaffold model.

[0084] The high-stress areas and curves from the Gyroid scaffold model obtained from Mathematica software were imported into Solidworks software for modeling to obtain an optimized Gyroid scaffold model (see reference). Figure 11 (As shown). In this embodiment, when the angle range between the gradient direction and the compression direction in the mathematical expression of the Gyroid scaffold model (i.e., the difference between the maximum and minimum angle values) is 40° or 60°, the optimized Gyroid scaffold model "G7040; G7060" can be obtained, where "G" represents the three-period minimal surface structure as Gyroid, "70" represents the overall porosity of the structure as 70%, and "40 or 60" represents the difference between the maximum and minimum angles between the gradient direction and the compression direction in the mathematical expression of the Gyroid scaffold model (i.e., the angle range of the optimization region) as 40° or 60°. A schematic diagram of the optimized Gyroid scaffold model "G7040; G7060" is shown below. Figure 13 As shown ("G70" is the Gyroid support model before optimization).

[0085] The high-stress marked areas of the Diamond scaffold model were thickened with a smooth transition (maximum thickening factor of 2 times, controlling the porosity of the thickened Diamond scaffold model to 70%) to obtain the optimized Diamond scaffold model.

[0086] Using Mathematica software and based on parametric control equations, the curve in the mathematical expression of the Diamond scaffold model with a gradient direction at a 90° angle to the compression direction was extracted (see reference). Figure 9 and Figure 10 As shown), the parameter control equations are: .

[0087] in, The mathematical expression for the Diamond scaffold model; This represents the angle between the gradient direction and the compression direction in the mathematical expression of the Diamond scaffold model.

[0088] The high-stress areas and curves from the Diamond scaffold model obtained from Mathematica software were imported into Solidworks software for modeling to obtain an optimized Diamond scaffold model (see reference). Figure 12(As shown). In this embodiment, when the angle range between the gradient direction and the compression direction in the mathematical expression of the Diamond scaffold model (i.e., the difference between the maximum and minimum angle values) is 40° or 60°, the optimized Diamond scaffold model "D7040; D7060" can be obtained, where "D" represents the three-period minimum surface structure as Diamond, "70" represents the overall porosity of the structure as 70%, and "40 or 60" represents the difference between the maximum and minimum angles between the gradient direction and the compression direction in the mathematical expression of the Diamond scaffold model (i.e., the angle range of the optimization region) as 40° or 60°. A schematic diagram of the optimized Diamond scaffold model "D7040; D7060" is shown below. Figure 14 As shown ("D70" is the Diamond scaffold model before optimization).

[0089] Step 105. Perform mechanical compression simulation on the optimized Gyroid scaffold model to determine the optimization effect, and simultaneously perform mechanical compression simulation on the optimized Diamond scaffold model to determine the optimization effect.

[0090] In this embodiment, mechanical compression simulation is performed on the optimized Gyroid scaffold model to determine the optimization effect, including:

[0091] The optimized Gyroid scaffold model was imported into 3-matic software in .stl format for 2D and 3D mesh generation. The optimized Gyroid scaffold model after mesh generation was then imported into the Abaqus platform in .inp format for mechanical compression simulation. The stress-strain curves of the optimized Gyroid scaffold model were exported. The strain curves of the unoptimized Diamond scaffold model "G70" and the optimized Diamond scaffold models "G7040" and "G7060" were used as references. Figure 15As shown, the yield strength and elastic modulus of the optimized Gyroid scaffold model were calculated based on the stress-strain curve, and the optimization effect of the Gyroid scaffold model was determined based on the yield strength and elastic modulus of the optimized Gyroid scaffold model. In this embodiment, the yield strength of the unoptimized Gyroid scaffold model "G70" was 122.271 MPa, and the elastic modulus was 12.627 GPa; the yield strength of the optimized Gyroid scaffold model "G7040" was 143.959 MPa, and the elastic modulus was 14.423 GPa; the yield strength of the optimized Gyroid scaffold model "G7060" was 152.799 MPa, and the elastic modulus was 15.011 GPa. The results show that the yield strength of the optimized Gyroid scaffold models is higher than that of the unoptimized Gyroid scaffold models, and the elastic modulus of the optimized Gyroid scaffold models is within the elastic modulus range of natural cortical bone (3-30 GPa). Therefore, the stent with optimized wall thickness obtained through the method of this embodiment is more conducive to supporting the weight of the human body and is less prone to stress shielding.

[0092] Mechanical compression simulations were performed on the optimized Diamond scaffold model to determine the optimization effect, including:

[0093] The optimized Diamond support model was imported into 3-matic software in .stl format for 2D and 3D mesh generation. The optimized Diamond support model after mesh generation was then imported into the Abaqus platform in .inp format for mechanical compression simulation. The stress-strain curves of the optimized Diamond support model were exported. The strain curves of the unoptimized Diamond support model "D70" and the optimized Diamond support models "D7040" and "D7060" are referenced. Figure 16As shown, the yield strength and elastic modulus of the optimized Diamond scaffold model were calculated based on the stress-strain curve, and the optimization effect of the Diamond scaffold model was determined based on the yield strength and elastic modulus of the optimized Diamond scaffold model. In this embodiment, the yield strength of the Diamond scaffold model "D70" before optimization was 150.608 MPa, and the elastic modulus was 16.811 GPa; the yield strength of the optimized Diamond scaffold model "D7040" was 175.319 MPa, and the elastic modulus was 22.091 GPa; the yield strength of the optimized Diamond scaffold model "D7060" was 191.730 MPa, and the elastic modulus was 22.646 GPa. The results show that the yield strength of the optimized Diamond scaffold models is higher than that of the unoptimized Diamond scaffold models, and the elastic modulus of the optimized Diamond scaffold models is within the range of the elastic modulus of natural cortical bone (3-30 GPa). Therefore, the stent with optimized wall thickness obtained through the method of this embodiment is more conducive to supporting the weight of the human body and is less prone to stress shielding.

[0094] Although the subject matter has been described using language specific to structural features and / or methodological logic, it should be understood that the subject matter defined in the appended claims is not necessarily limited to the specific features or actions described above. Rather, the specific features and actions described above are merely illustrative examples of implementing the claims.

Claims

1. A stress-guided method for optimizing the wall thickness of a minimal curved surface bone scaffold, characterized in that, include: Step 101. Construct a Gyroid scaffold model with a Sheet configuration based on the Gyroid-type implicit equations in the three-period minimal surface, and simultaneously construct a Diamond scaffold model with a Sheet configuration based on the Diamond-type implicit equations in the three-period minimal surface. Step 102. Perform mechanical compression simulation on the Gyroid scaffold model to determine the high-stress areas of the Gyroid scaffold model, and simultaneously perform mechanical compression simulation on the Diamond scaffold model to determine the high-stress areas of the Diamond scaffold model. Step 103. Determine the stress law based on the high-stress region of the Gyroid scaffold model, and mark the high-stress region in the Gyroid scaffold model using the stress law to obtain the high-stress marked region of the Gyroid scaffold model; at the same time, determine the stress law based on the high-stress region of the Diamond scaffold model, and mark the high-stress region in the Diamond scaffold model using the stress law to obtain the high-stress marked region of the Diamond scaffold model. Step 104. Smoothly thicken the high-stress marked area of ​​the Gyroid scaffold model to obtain the optimized Gyroid scaffold model, and smoothly thicken the high-stress marked area of ​​the Diamond scaffold model to obtain the optimized Diamond scaffold model. Step 105. Perform mechanical compression simulation on the optimized Gyroid scaffold model to determine the optimization effect, and simultaneously perform mechanical compression simulation on the optimized Diamond scaffold model to determine the optimization effect.

2. The method according to claim 1, characterized in that, In step 101, the Gyroid-type implicit equations in the Gyroid scaffold model with a Sheet configuration, constructed based on the Gyroid-type implicit equations in the three-period minimal surface, are as follows: ， Where L represents the unit cell size, and C is the bias function used to adjust the Gyroid-type implicit equation.

3. The method according to claim 2, characterized in that, In step 101, the Diamond-type implicit equations in the Diamond-type implicit equations constructed based on the three-period minimal surface to form the Diamond scaffold model with a Sheet configuration are as follows: ， Where L represents the unit cell size, and C is the bias function used to adjust the Diamond-type implicit equation.

4. The method according to claim 1, characterized in that, In step 102, performing mechanical compression simulation on the Gyroid scaffold model to determine the high-stress areas of the Gyroid scaffold model includes: The Gyroid scaffold model was imported into 3-matic software in .stl format for two-dimensional and three-dimensional mesh generation. The meshed Gyroid scaffold model was then imported into the Abaqus platform in .inp format for mechanical compression simulation to obtain the stress cloud map of the Gyroid scaffold model. The high-stress areas of the Gyroid scaffold model were determined through the stress cloud map.

5. The method according to claim 4, characterized in that, In step 102, performing mechanical compression simulation on the Diamond support model to determine the high-stress areas of the Diamond support model includes: The Diamond support model was imported into 3-matic software in .stl format for two-dimensional and three-dimensional mesh generation. The meshed Diamond support model was then imported into the Abaqus platform in .inp format for mechanical compression simulation to obtain the stress cloud map of the Diamond support model. The high-stress areas of the Diamond support model were determined through the stress cloud map.

6. The method according to claim 1, characterized in that, In step 103, the high-stress areas in the Gyroid scaffold model are marked according to the stress law to obtain the high-stress marked areas of the Gyroid scaffold model. Specifically, these high-stress marked areas are as follows: The high-stress regions in the Gyroid scaffold model were marked using Mathematica software and the angle between the gradient direction and the compression direction in the mathematical expression of the Gyroid scaffold model. The angle between the gradient direction and the compression direction in the mathematical expression of the Gyroid scaffold model satisfies the following formula: ， in, For the mathematical expression of the Gyroid scaffold model; This represents the angle between the gradient direction and the compression direction in the mathematical expression of the Gyroid scaffold model. This represents the minimum angle between the gradient direction and the compression direction in the mathematical expression of the Gyroid scaffold model. This represents the maximum angle between the gradient direction and the compression direction in the mathematical expression of the Gyroid scaffold model.

7. The method according to claim 6, characterized in that, In step 103, marking the high-stress areas in the Diamond support model based on the stress pattern to obtain the high-stress marked areas of the Diamond support model is specifically as follows: The high-stress regions in the Diamond scaffold model were marked using Mathematica software and the angle between the gradient direction and the compression direction in the mathematical expression of the Diamond scaffold model. The angle between the gradient direction and the compression direction in the mathematical expression of the Diamond scaffold model satisfies the following formula: ， in, The mathematical expression for the Diamond scaffold model; This represents the angle between the gradient direction and the compression direction in the mathematical expression of the Diamond scaffold model. This represents the minimum angle between the gradient direction and the compression direction in the mathematical expression of the Diamond scaffold model. This represents the maximum angle between the gradient direction and the compression direction in the mathematical expression of the Diamond scaffold model.

8. The method according to claim 7, characterized in that, In step 104, the high-stress marked area of ​​the Gyroid scaffold model is thickened with a smooth transition to obtain the optimized Gyroid scaffold model. Specifically, this involves: Using Mathematica software and based on the parametric control equations, the curve with a 90° angle between the gradient direction and the compression direction in the mathematical expression of the Gyroid scaffold model was extracted. The parametric control equations are as follows: ，， in, For the mathematical expression of the Gyroid scaffold model; This represents the angle between the gradient direction and the compression direction in the mathematical expression of the Gyroid scaffold model. The high-stress areas and curves in the Gyroid scaffold model obtained from Mathematica software were imported into Solidworks software for modeling to obtain an optimized Gyroid scaffold model.

9. The method according to claim 8, characterized in that, In step 104, the high-stress marked area of ​​the Diamond scaffold model is thickened with a smooth transition to obtain the optimized Diamond scaffold model. Specifically, this involves: Using Mathematica software and based on the parametric control equations, the curve with a 90° angle between the gradient direction and the compression direction in the mathematical expression of the Diamond scaffold model was extracted. The parametric control equations are as follows: ， in, The mathematical expression for the Diamond scaffold model; This represents the angle between the gradient direction and the compression direction in the mathematical expression of the Diamond scaffold model. The high-stress areas and curves in the Diamond scaffold model obtained from Mathematica software were imported into Solidworks software for modeling to obtain an optimized Diamond scaffold model.

10. The method according to claim 1, characterized in that, In step 105, mechanical compression simulation is performed on the optimized Gyroid scaffold model to determine the optimization effect, including: The optimized Gyroid scaffold model was imported into 3-matic software in .stl format for two-dimensional and three-dimensional mesh generation. The optimized Gyroid scaffold model after mesh generation was then imported into the Abaqus platform in .inp format for mechanical compression simulation. The stress-strain curves of the optimized Gyroid scaffold model were exported. Based on the stress-strain curves, the yield strength and elastic modulus of the optimized Gyroid scaffold model were calculated. The optimization effect of the Gyroid scaffold model was determined based on the yield strength and elastic modulus of the optimized Gyroid scaffold model. Mechanical compression simulations were performed on the optimized Diamond scaffold model to determine the optimization effect, including: The optimized Diamond support model was imported into 3-matic software in .stl format for two-dimensional and three-dimensional mesh generation. The optimized Diamond support model after mesh generation was then imported into the Abaqus platform in .inp format for mechanical compression simulation. The stress-strain curves of the optimized Diamond support model were exported. Based on the stress-strain curves, the yield strength and elastic modulus of the optimized Diamond support model were calculated. The optimization effect of the Diamond support model was determined based on the yield strength and elastic modulus of the optimized Diamond support model.

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