A method for designing and manufacturing a continuous fiber reinforced artificial limb

Abstract

The application discloses a kind of continuous fiber reinforced artificial limb design and manufacture method, comprising the following steps: based on human prosthesis data, obtain inner liner design domain;Based on the inner liner design domain, obtain inner liner model by optimization;Based on the inner liner model, obtain reinforcing layer fiber arrangement model by optimization;Based on the inner liner model, 3D printing is made to inner liner;And based on the reinforcing layer fiber arrangement model, fiber reinforced layer is printed on the inner liner surface, and the continuous fiber reinforced artificial limb is obtained.The application is optimized by two-stage design to obtain light weight, high strength inner liner structure and fiber reinforced layer structure that can fully exert the high strength and comfort of fiber composite, then uses step-by-step manufacturing strategy, first prints and manufactures inner liner, then prints and manufactures fiber reinforced layer on the inner liner surface, so as to realize the rapid manufacturing of artificial limb, and ensure that artificial limb is highly personalized, has high bearing capacity and light weight.

Description

Technical Field

[0001] This invention relates to the field of prosthesis design and manufacturing, and in particular to a method for designing and manufacturing a continuous fiber reinforced artificial prosthesis. Background Technology

[0002] As an important medical rehabilitation device, prosthetic limbs are an essential part of the daily lives of people with limb disabilities. In recent years, with industrialization and the aging population, cases of limb injuries caused by engineering and traffic accidents, as well as accidents involving the elderly, have been rising year by year, making the demand for prosthetic limbs even more urgent. Traditional prosthetic limbs are mainly manufactured using materials such as wood, leather, metal, or plastic through subtractive manufacturing techniques. On the one hand, this results in a large amount of waste, reducing resource utilization; on the other hand, it leads to inherent drawbacks such as low durability, long manufacturing cycles, and poor personalization of current prosthetic limbs.

[0003] To address the urgent need for lightweight, comfortable, and durable prosthetics among people with limb disabilities, current technologies utilize continuous fiber-reinforced materials in prosthetic manufacturing. This involves first fabricating an inner liner containing the prosthetic socket, then winding continuous carbon fiber reinforcement around the liner to obtain a prosthetic with a fiber-reinforced layer. However, traditional prosthetic manufacturing techniques struggle to achieve precise fabrication of continuous fiber-reinforced prostheses, limiting fiber placement to a uniform angle. Furthermore, while emerging 3D printing technologies exist, current design and fabrication methods are limited to optimizing prosthetic size and shape, failing to simultaneously consider both the prosthetic configuration and the path of the continuous fibers. Therefore, current methods for designing and manufacturing continuous fiber-reinforced prostheses cannot fully leverage the advantages of fiber-reinforced composite materials, making it difficult to achieve the high strength and comfort of continuous fiber-reinforced composite prostheses.

[0004] Therefore, existing technologies still need improvement and development. Summary of the Invention

[0005] In view of the shortcomings of the prior art, the purpose of this invention is to provide a design and manufacturing method for a continuous fiber reinforced artificial limb, so as to solve the problem that the advantages of fiber reinforced composite materials cannot be fully utilized in the prior art, and it is difficult to achieve the high strength and comfort of continuous fiber reinforced composite material prostheses.

[0006] The technical solution of the present invention is as follows:

[0007] A method for designing and fabricating a continuous fiber reinforced prosthesis includes the following steps:

[0008] Based on human prosthetic data, obtain the design domain of the inner lining layer;

[0009] Based on the inner liner design domain, the inner liner model is optimized and obtained;

[0010] Based on the inner liner model, the fiber arrangement model of the reinforcing layer is optimized.

[0011] Based on the aforementioned liner model, the liner is fabricated using 3D printing.

[0012] Based on the fiber arrangement model of the reinforcing layer, a fiber reinforcing layer is printed on the surface of the inner lining layer to obtain the continuous fiber-reinforced prosthesis.

[0013] In one implementation, the inner liner model is optimized based on the inner liner design domain, specifically including:

[0014] Determine the material of the inner lining layer for printing the inner lining layer;

[0015] To obtain force data of human prostheses;

[0016] Based on the inner lining material and the stress data, the boundary conditions of the inner lining are obtained;

[0017] Based on the boundary conditions, the first objective function is minimized to obtain the inner lining model.

[0018] In one implementation, the inner liner model is obtained by minimizing the first objective function based on the boundary conditions, specifically including:

[0019] The structural flexibility of the inner lining is obtained based on the global displacement vector and global stiffness matrix of the inner lining.

[0020] Obtain the first objective function, which is a weighted sum of the volume of the inner liner and the structural flexibility;

[0021] By minimizing the first objective function under the boundary conditions, the inner lining model is obtained.

[0022] In one embodiment, the liner material comprises a non-fiber-reinforced flexible thermoplastic material.

[0023] In one implementation, based on the inner liner model, an optimized fiber arrangement model for the reinforcing layer is obtained, specifically including:

[0024] Based on the liner model and the boundary conditions, the second objective function is minimized to determine the fiber angle and fiber content;

[0025] The fiber vector field of the reinforcing layer is determined based on the fiber angle and the fiber content;

[0026] Based on the fiber vector field of the reinforcing layer, a continuous fiber path is determined as the fiber arrangement model of the reinforcing layer.

[0027] In one implementation, based on the liner model and the boundary conditions, minimizing the second objective function to determine the fiber angle and fiber content specifically includes:

[0028] Obtain the second objective function, which is the p-norm of the structural failure factor;

[0029] Using the boundary conditions and the maximum value of the structural failure factor as constraints, the second objective function is minimized to determine the fiber angle and the fiber content.

[0030] In one embodiment, based on the fiber arrangement model of the reinforcing layer, a fiber reinforcing layer is printed on the surface of the inner liner layer to obtain the continuous fiber-reinforced prosthesis, specifically including:

[0031] The inner lining layer is transferred to a multi-degree-of-freedom printing platform;

[0032] Based on the fiber arrangement model of the reinforcing layer, the continuous fiber path is printed on the surface of the inner liner layer;

[0033] A filler material is printed around the continuous fiber path to form the fiber reinforcement layer, resulting in the continuous fiber reinforced prosthesis.

[0034] In one embodiment, the continuous fiber path comprises carbon fiber material, and the filler material comprises thermoplastic material.

[0035] In one implementation, before obtaining the lining design domain based on human prosthesis data, the following steps are included:

[0036] 3D scanning of intact human limbs to obtain point cloud data of the intact limbs;

[0037] The point cloud data is processed symmetrically to obtain the human prosthesis data.

[0038] The present invention also discloses a continuous fiber reinforced prosthesis, which is manufactured by the design and manufacturing method of the continuous fiber reinforced prosthesis described in any of the above claims.

[0039] In summary, this invention discloses a method for designing and manufacturing a continuous fiber-reinforced prosthesis, comprising the following steps: obtaining an inner liner design domain based on human prosthesis data; optimizing an inner liner model based on the inner liner design domain; optimizing a reinforcing layer fiber arrangement model based on the inner liner model; 3D printing the inner liner based on the inner liner model; and printing a fiber reinforcing layer on the surface of the inner liner based on the reinforcing layer fiber arrangement model to obtain the continuous fiber-reinforced prosthesis. This invention optimizes a lightweight, high-strength inner liner structure and a fiber reinforcing layer structure that fully utilizes the high strength and comfort of fiber composite materials through a two-stage design. Then, using a step-by-step manufacturing strategy, the inner liner is first printed, and then the fiber reinforcing layer is printed on the surface of the inner liner, thereby achieving rapid manufacturing of the prosthesis and ensuring high personalization, strong load-bearing capacity, and lightweight prosthesis. Attached Figure Description

[0040] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0041] Figure 1 This is a flowchart illustrating the steps of the design and fabrication method for the continuous fiber reinforced artificial limb described in this invention.

[0042] Figure 2 This is a schematic diagram illustrating the process of designing a human lower limb prosthesis in one embodiment of the continuous fiber reinforced artificial limb design and fabrication method of the present invention.

[0043] Figure 3 This is a schematic diagram illustrating the process of fabricating a human lower limb prosthesis in one embodiment of the design and fabrication method of the continuous fiber reinforced artificial limb described in this invention. Detailed Implementation

[0044] This application provides a method for designing and manufacturing a continuous fiber reinforced prosthesis. To make the objectives, technical solutions, and effects of this application clearer and more explicit, the following detailed description is provided with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only for explaining this application and are not intended to limit this application.

[0045] Those skilled in the art will understand that, unless specifically stated otherwise, the singular forms “a,” “an,” “the,” and “the” used herein may also include the plural forms. It should be further understood that the term “comprising” as used in this application means the presence of the stated features, integers, steps, operations, elements, and / or components, but does not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups thereof. It should be understood that when we say an element is “connected” or “coupled” to another element, it can be directly connected or coupled to the other element, or there may be intermediate elements. Furthermore, “connected” or “coupled” as used herein can include wireless connections or wireless coupling. The term “and / or” as used herein includes all or any units and all combinations of one or more associated listed items.

[0046] Furthermore, if the embodiments of this invention involve descriptions such as "first" or "second," these descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, features defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. If the combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed by this invention.

[0047] It will be understood by those skilled in the art that, unless otherwise defined, all terms used herein (including technical and scientific terms) have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains. It should also be understood that terms such as those defined in general dictionaries should be understood to have the same meaning as in the context of the prior art, and should not be interpreted in an idealized or overly formal sense unless specifically defined as herein.

[0048] As one of the most typical 3D printing technologies, fused deposition modeling (FDM) employs a layer-by-layer manufacturing principle, enabling the formation of structures with complex shapes. For continuous fiber reinforced composite (CFRP) structures, 3D printing allows for point-by-point and domain-by-domain control of material and fiber distribution to meet more complex performance requirements. However, current prosthetic design methods are often limited to size and shape optimization, failing to address the design of CFRP prostheses and resulting in designs that do not meet the manufacturing requirements of 3D printing. To maximize the strength and comfort of CFRP prostheses, the prosthesis configuration and the path of the continuous fibers should be considered simultaneously during the design phase to fully leverage the advantages of fiber-reinforced composites.

[0049] This invention discloses a method for designing and manufacturing a continuous fiber reinforced prosthesis, comprising the following steps: obtaining an inner lining design domain based on human prosthesis data; optimizing an inner lining model based on the inner lining design domain; optimizing a reinforcement layer fiber arrangement model based on the inner lining model; 3D printing the inner lining based on the inner lining model; and printing a fiber reinforcement layer on the surface of the inner lining based on the reinforcement layer fiber arrangement model to obtain the continuous fiber reinforced prosthesis.

[0050] Furthermore, based on the inner lining design domain, the inner lining model is optimized, specifically including: determining the inner lining material for printing the inner lining; obtaining the stress data of the human prosthesis; obtaining the boundary conditions of the inner lining based on the inner lining material and the stress data; and minimizing the first objective function based on the boundary conditions to obtain the inner lining model.

[0051] Further, based on the boundary conditions, minimizing the first objective function to obtain the inner lining model specifically includes: obtaining the structural flexibility of the inner lining based on the global displacement vector and global stiffness matrix of the inner lining; obtaining the first objective function, which is a weighted sum of the volume of the inner lining and the structural flexibility; and minimizing the first objective function with the boundary conditions as constraints to obtain the inner lining model.

[0052] Furthermore, the inner lining material comprises a non-fiber-reinforced flexible thermoplastic material.

[0053] Furthermore, based on the inner liner model, an optimized fiber arrangement model for the reinforcing layer is obtained, specifically including: minimizing a second objective function based on the inner liner model and the boundary conditions to determine the fiber angle and fiber content; determining the fiber vector field of the reinforcing layer based on the fiber angle and the fiber content; and determining a continuous fiber path as the fiber arrangement model of the reinforcing layer based on the fiber vector field of the reinforcing layer.

[0054] Furthermore, based on the liner model and the boundary conditions, minimizing the second objective function to determine the fiber angle and fiber content specifically includes: obtaining the second objective function, where the second objective function is the p-norm of the structural failure factor; and minimizing the second objective function using the boundary conditions and the maximum value of the structural failure factor as constraints to determine the fiber angle and fiber content.

[0055] Furthermore, based on the fiber arrangement model of the reinforcing layer, a fiber reinforcing layer is printed on the surface of the inner liner to obtain the continuous fiber-reinforced prosthesis. Specifically, this includes: transferring the inner liner to a multi-degree-of-freedom printing platform; printing the continuous fiber path on the surface of the inner liner based on the fiber arrangement model of the reinforcing layer; and printing filler material around the continuous fiber path to form the fiber reinforcing layer, thereby obtaining the continuous fiber-reinforced prosthesis.

[0056] Furthermore, the continuous fiber path includes carbon fiber material, and the filler material includes thermoplastic material.

[0057] Furthermore, before obtaining the inner lining design domain based on the human prosthesis data, the process includes: three-dimensional scanning of the intact human limb to obtain point cloud data of the intact limb; and symmetrical processing of the point cloud data to obtain the human prosthesis data.

[0058] This invention relates to a continuous fiber-reinforced prosthesis manufactured using a design and fabrication method. The method employs a two-stage design approach, optimizing the design of the inner liner and the fiber reinforcement layer on its surface. Then, 3D printing technology is used for step-by-step manufacturing. First, the inner liner is manufactured layer by layer using a fused deposition modeling (FDM) process. Next, using the inner liner as a printing support, reinforcing fibers are laid along a pre-designed fiber path on the inner liner surface, while simultaneously filling with a thermoplastic matrix material to complete the fiber reinforcement layer. This method enables rapid manufacturing of continuous fiber-reinforced prostheses, providing highly personalized, high-load-bearing, and lightweight continuous fiber-reinforced prosthesis structures.

[0059] Specifically, such as Figure 1 As shown, the design and fabrication method of a continuous fiber reinforced artificial prosthesis according to the present invention includes the following steps:

[0060] S100. Based on human prosthetic data, obtain the inner lining design domain.

[0061] Specifically, the human prosthesis data includes data such as the force distribution of the prosthesis for the user requiring it. Due to differences in body shape, physique, and movement patterns among users, their needs for prostheses vary. Therefore, it is necessary to collect human prosthesis data for different users to ensure that the designed and manufactured prostheses meet personalized requirements. Further, a 3D scan of the intact limb is performed to obtain point cloud data of the intact limb, which is the limb for which the corresponding user requires a prosthesis. Based on the symmetry of the human body, the point cloud data is symmetrically processed to obtain the human prosthesis data. This human prosthesis data matches the user's needs, enabling personalized customization services.

[0062] After acquiring the human prosthesis data, a design domain for the inner lining layer is formed based on the human prosthesis data. The inner lining layer is designed based on this design domain to ensure that the artificial prosthesis finally designed and manufactured matches the user's residual limb and avoids additional damage caused by mismatch of the inner lining layer during installation and use.

[0063] Furthermore, such as Figure 1 As shown, after step S100, the following step is also included:

[0064] S200. Based on the inner lining design domain, the inner lining model is optimized.

[0065] Specifically, the material for the lining layer is first determined, and data on the hand of a human prosthesis is acquired. Based on the lining layer material and the stress data, the boundary conditions of the lining layer are obtained. Finally, based on the boundary conditions, a first objective function is minimized to obtain the lining layer model applicable to 3D printing. Specifically, the structural flexibility of the lining layer is obtained based on its global displacement vector and global stiffness matrix. The weighted sum of the lining layer's volume and the structural flexibility is used as the first objective function, and the boundary conditions are used as optimization constraints. Minimizing the first objective function yields a lightweight and stiff lining layer model.

[0066] In one embodiment, a fiber-free, flexible thermoplastic material is used as the inner lining material. Boundary conditions are determined based on the material used and the stress conditions of the human lower limb. Then, with the overall stiffness and volume of the inner lining as optimization objectives, a topology optimization algorithm based on isotropic materials is used to perform topology optimization design within the design domain, thereby obtaining the inner lining structure of the artificial prosthesis as the inner lining model. Optionally, the topology optimization design can determine the unstressed parts of the inner lining while ensuring the overall support strength of the inner lining. The structure of the inner lining can be designed by hollowing out or subtractive materials to obtain a lightweight and high-strength inner lining model.

[0067] Specifically, the optimization model for the inner lining layer is as follows:

[0068]

[0069] in Let Ω0 represent the liner structure, and let V(Ω) be the design domain, representing the design of the liner structure within that domain. The objective function J1 is expressed as a weighted sum of the liner volume and structural flexibility, where λ is a weighting factor, c represents the structural flexibility of the liner, and V(Ω) represents the volume of the liner structure. The structural flexibility is inversely proportional to the structural stiffness, and can be expressed as c = u T Ku, where u is the global displacement vector and K is the global stiffness matrix. The boundary condition constraint a(u,w,Ω)=l(w,Ω) is the equilibrium equation expressed in weak form, where a(u,w,Ω) is the bilinear energy function and l(w,Ω) is the unilinear load function, specifically expressed as follows:

[0070] a(u,w,Ω)=∫ Ω ε(u)Eε(w)dΩ

[0071]

[0072] Where u and w are the actual displacement field and the virtual displacement field, respectively, ε is the strain field, f and p represent the body force and the surface force, respectively, and E is the elastic tensor of the inner lining material. The corresponding data can be obtained by combining the properties of the selected inner lining material and the stress condition of the artificial prosthesis. By minimizing the first objective function J1, a lightweight and stiff inner lining structure can be obtained.

[0073] Furthermore, such as Figure 1 As shown, after step S200, the following step is also included:

[0074] S300. Based on the inner liner model, the fiber arrangement model of the reinforcing layer is optimized.

[0075] Specifically, firstly, based on the inner liner model and the boundary conditions, a second objective function is minimized to determine the fiber angle and fiber content; then, based on the fiber angle and fiber content, the reinforcing layer fiber vector field is determined; finally, based on the reinforcing layer fiber vector field, a continuous fiber path is determined as the reinforcing layer fiber arrangement model. Since the fiber reinforcing layer is printed on the surface of the inner liner, the design domain of the reinforcing layer fiber arrangement model is limited to the inner liner design domain, and the same boundary conditions are used. Further, the second objective function is constructed as the p-norm of the structural failure factor. The smaller the second objective function, the greater the structural strength of the fiber reinforcing layer arrangement model. Using the boundary conditions and the maximum value of the structural failure factor as constraints, the second objective function is minimized to determine the fiber angle and fiber content of each fiber in the fiber reinforcing layer during the printing process under optimized conditions, thereby determining the reinforcing layer fiber vector field. After determining the reinforcing layer fiber vector field, a streamline generation algorithm is used to capture fiber distribution information, thereby generating streamlines to determine the continuous fiber path and optimizing the reinforcing layer fiber arrangement model.

[0076] In one implementation, the inner lining layer is used as the design domain for the fiber reinforcement layer. Under the same boundary conditions, with fiber angle and fiber content as design variables and the strength of the fiber reinforcement layer as the optimization objective, a gradient descent-based optimization algorithm is used to design the fiber angle and fiber content, thereby determining the fiber vector field of the fiber reinforcement layer. Optionally, by adjusting the fiber angle and fiber content, the printability of continuous fibers on the surface of the inner lining layer is first ensured, meaning that existing 3D printing platforms can be used to lay continuous fibers on demand at specific locations on the surface of the inner lining layer. Simultaneously, the continuous fibers are ensured to provide the necessary support for the overall prosthesis, enhancing the overall mechanical properties of the prosthesis while ensuring user comfort.

[0077] Specifically, the optimization model for the fiber reinforcement layer is as follows:

[0078]

[0079] Where θ and v θ The fiber angle and fiber content of the structural units in the fiber-reinforced layer are represented. The second objective function J2 is the P-norm of the structural failure factor γ. The smaller the second objective function J2, the smaller the overall failure factor of the fiber-reinforced layer, and thus the greater the structural strength. The structural failure factor γ is generally constructed using strength criteria for continuous fiber-reinforced composite materials (such as the Tsai-Hill and Tsai-Wu strength criteria). Of the two constraints serving as boundary conditions, one is the maximum failure factor constraint, γ. cThe first constraint represents the maximum allowable failure factor of the structure, and the second constraint is the equilibrium equation expressed in weak form, where a(u,w,Ω,θ,v) θ The expression is as follows:

[0080] a(u,w,Ω,θ,ν θ )=∫ Ω ε(u)E(θ,v θ )ε(w)dΩ

[0081] E(θ,v θ ) is the elastic tensor of the fiber reinforcement layer material, which is related to the fiber angle and fiber content. The second objective function is minimized to obtain the fiber angle and fiber content required during the printing process, thereby determining the fiber vector field of the fiber reinforcement layer. Then, based on the optimized fiber vector field, and using three-dimensional flow field theory, a streamline generation algorithm is employed to capture fiber distribution information, thereby generating streamlines to determine continuous fiber paths, completing the design of the fiber reinforcement layer in the prosthesis, and obtaining an optimized fiber arrangement model for the reinforcement layer.

[0082] Furthermore, such as Figure 1 As shown, after step S300, the following step is also included:

[0083] S400. Based on the inner lining model, the inner lining is 3D printed.

[0084] Specifically, the inner liner is manufactured layer by layer using a fused deposition modeling process. The inner liner material includes a non-fiber-reinforced flexible thermoplastic material. Optionally, the inner liner material is TPU, NinjaFlex, etc.

[0085] Furthermore, such as Figure 1 As shown, after step S400, the following step is also included:

[0086] S500. Based on the fiber arrangement model of the reinforcing layer, a fiber reinforcing layer is printed on the surface of the inner lining layer to obtain the continuous fiber-reinforced prosthesis.

[0087] Specifically, after the inner lining layer is printed layer by layer, it is transferred to a multi-degree-of-freedom printing platform to ensure that continuous fibers can be printed and laid out on the surface of the inner lining layer at any angle and direction. After transferring the inner lining layer to the multi-degree-of-freedom printing platform, based on the fiber arrangement model of the reinforcing layer, the continuous fiber path is printed on the surface of the inner lining layer. After laying out the designed continuous fibers on the surface of the inner lining layer, filler material is printed around the continuous fiber path to form the fiber reinforcement layer, resulting in the continuous fiber reinforced prosthesis. In this way, with the inner lining layer as a support, continuous fibers are laid out on the surface of the inner lining layer according to the designed structure, ensuring that the continuous fibers can provide the required rigidity and support. Then, the filler material covers the continuous fibers to form the fiber reinforcement layer, thereby ensuring that the appearance of the entire prosthesis is uniform and aesthetically pleasing, while avoiding wear on the continuous fibers during use and extending the service life of the prosthesis. The artificial prosthesis produced by the continuous fiber reinforced artificial prosthesis design and manufacturing method of the present invention has the advantages of high personalization, strong load-bearing capacity and light weight. Moreover, it can be manufactured using existing 3D printing technology without the need to introduce additional equipment, thereby reducing manufacturing costs and making it easy to promote and apply.

[0088] Optionally, the continuous fiber is continuous carbon fiber, and the filler material is a thermoplastic material, such as PLA, ABS, etc.

[0089] The design and fabrication method of the continuous fiber reinforced artificial limb of the present invention will be further described below with reference to the accompanying drawings.

[0090] like Figure 2The diagram illustrates a flowchart of the design and fabrication method for a continuous fiber-reinforced artificial limb according to the present invention, illustrating the design of a lower limb prosthesis in one embodiment. The overall prosthetic structure is designed in two stages. First, a three-dimensional scan of the intact lower limb is performed and then flipped to obtain the design domain of the desired prosthesis. Next, topology optimization is performed to determine the structure of the inner lining layer. The structure of the inner lining layer is adjusted without affecting the overall stiffness, and a hollowed-out design reduces the overall weight for ease of use. Finally, fiber optimization is performed on the surface of the designed inner lining layer to determine the arrangement of continuous fibers within the fiber reinforcement layer corresponding to the surface of the inner lining layer. This yields the fiber reinforcement layer structure corresponding to the inner lining layer. Continuous fibers are laid out while ensuring the inner lining layer achieves high strength and light weight, thus enhancing the mechanical strength of the overall prosthetic structure. Therefore, the present invention uses a two-stage design method to design a continuous fiber-reinforced composite material artificial limb. First, a topology optimization algorithm is used to perform topology optimization within the design domain of the inner liner layer, resulting in the inner liner structure. Then, using the inner liner layer as the design domain for the reinforcement layer, the fiber angles and fiber densities are optimized under the same boundary conditions to determine the fiber vector field of the reinforcement layer. Finally, a streamline generation algorithm is used to generate continuous fiber paths. This two-stage design method can achieve highly personalized, high-load-bearing, and lightweight continuous fiber-reinforced prosthetic limb structures.

[0091] like Figure 3 The diagram illustrates a process for manufacturing a human lower limb prosthesis using the continuous fiber reinforced prosthesis design and fabrication method described in this invention, as shown in one embodiment. After designing and optimizing the inner liner and fiber reinforcement layer, the continuous fiber reinforced prosthesis is manufactured step-by-step using printing. First, on a printing platform, the inner liner is printed layer-by-layer using a flexible matrix material printhead via fused deposition modeling (FDM) based on the designed inner liner model. Then, the inner liner is transferred to a rotatable fixture on a multi-degree-of-freedom printing platform. Using a fiber prepreg printhead, continuous carbon fibers are laid on the surface of the inner liner along the fiber placement path within the designed reinforcement layer fiber arrangement model. After all continuous fibers are laid, the process is switched to a matrix material printhead, which uses thermoplastic material to print filling material around the continuous fibers in the areas of the inner liner where no continuous fibers are laid, forming a fiber reinforcement layer and resulting in a complete prosthesis. Figure 3(d) is a schematic diagram of the final continuous fiber-reinforced prosthesis. The cross-sectional view along section A-A' shows that the overall structure involves laying continuous fibers on the surface of the inner lining layer, and then covering the continuous fibers with filling material to form the final fiber reinforcement layer. This design is aesthetically pleasing, lightweight, and ensures overall mechanical properties and strength, providing users with lightweight, high-load-bearing, and highly customizable prosthetic limbs. Therefore, this invention utilizes a step-by-step manufacturing strategy based on 3D printing technology. First, the inner lining layer is manufactured layer by layer using fused deposition modeling (FDM). Then, using the inner lining layer as a printing support, reinforcing fibers are laid along a pre-designed fiber path on the surface of the inner lining layer, while simultaneously filling with thermoplastic matrix material to complete the reinforcement layer. This step-by-step manufacturing strategy based on 3D printing technology facilitates the rapid manufacturing of fiber-reinforced composite material prostheses.

[0092] In summary, this invention discloses a method for designing and manufacturing a continuous fiber-reinforced prosthesis, comprising the following steps: obtaining an inner liner design domain based on human prosthesis data; optimizing an inner liner model based on the inner liner design domain; optimizing a reinforcing layer fiber arrangement model based on the inner liner model; 3D printing the inner liner based on the inner liner model; and printing a fiber reinforcing layer on the surface of the inner liner based on the reinforcing layer fiber arrangement model to obtain the continuous fiber-reinforced prosthesis. This invention optimizes a lightweight, high-strength inner liner structure and a fiber reinforcing layer structure that fully utilizes the high strength and comfort of fiber composite materials through a two-stage design. Then, using a step-by-step manufacturing strategy, the inner liner is first printed, and then the fiber reinforcing layer is printed on the surface of the inner liner, thereby achieving rapid manufacturing of the prosthesis and ensuring a high degree of personalization, strong load-bearing capacity, and lightweight prosthesis.

[0093] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application.

Claims

1. A method for designing and manufacturing a continuous fiber reinforced artificial prosthesis, characterized in that, Including the following steps: Based on human prosthetic data, obtain the design domain of the inner lining layer; Based on the inner liner design domain, the inner liner model is optimized and obtained; Based on the inner liner model, the fiber arrangement model of the reinforcing layer is optimized. Based on the aforementioned liner model, the liner is fabricated using 3D printing. Based on the fiber arrangement model of the reinforcing layer, a fiber reinforcing layer is printed on the surface of the inner liner to obtain the continuous fiber-reinforced prosthesis; Specifically, based on the inner liner design domain, the inner liner model is optimized and obtained, including: Determine the material of the inner lining layer for printing the inner lining layer; To obtain force data of human prostheses; Based on the inner lining material and the stress data, the boundary conditions of the inner lining are obtained; Based on the boundary conditions, the first objective function is minimized to obtain the inner lining model; The inner liner model is obtained by minimizing the first objective function based on the boundary conditions, specifically including: The structural flexibility of the inner lining is obtained based on the global displacement vector and global stiffness matrix of the inner lining. Obtain the first objective function, which is a weighted sum of the volume of the inner liner and the structural flexibility; By minimizing the first objective function under the boundary conditions, the inner lining model is obtained. Specifically, based on the inner liner model, the fiber arrangement model of the reinforcing layer is optimized, including: Based on the liner model and the boundary conditions, the second objective function is minimized to determine the fiber angle and fiber content; The fiber vector field of the reinforcing layer is determined based on the fiber angle and the fiber content; Based on the fiber vector field of the reinforcing layer, a continuous fiber path is determined as the fiber arrangement model of the reinforcing layer; Specifically, based on the fiber arrangement model of the reinforcing layer, a fiber reinforcing layer is printed on the surface of the inner lining layer to obtain the continuous fiber-reinforced prosthesis, which includes: The inner lining layer is transferred to a multi-degree-of-freedom printing platform; Based on the fiber arrangement model of the reinforcing layer, the continuous fiber path is printed on the surface of the inner liner layer; A filler material is printed around the continuous fiber path to form the fiber reinforcement layer, resulting in the continuous fiber reinforced prosthesis.

2. The method for designing and manufacturing a continuous fiber reinforced prosthesis according to claim 1, characterized in that, The inner lining material comprises a non-fiber-reinforced flexible thermoplastic material.

3. The method for designing and manufacturing a continuous fiber reinforced prosthesis according to claim 1, characterized in that, Based on the liner model and the boundary conditions, the second objective function is minimized to determine the fiber angle and fiber content, specifically including: Obtain the second objective function, which is the p-norm of the structural failure factor; Using the boundary conditions and the maximum value of the structural failure factor as constraints, the second objective function is minimized to determine the fiber angle and the fiber content.

4. The method for designing and manufacturing a continuous fiber reinforced prosthesis according to claim 1, characterized in that, The continuous fiber path includes carbon fiber material, and the filler material includes thermoplastic material.

5. The method for designing and manufacturing a continuous fiber reinforced prosthesis according to claim 1, characterized in that, Before obtaining the inner lining design domain based on human prosthetic data, the following steps are included: 3D scanning of intact human limbs to obtain point cloud data of the intact limbs; The point cloud data is processed symmetrically to obtain the human prosthesis data.

6. A continuous fiber-reinforced artificial prosthesis, characterized in that, It is manufactured by the design and fabrication method of continuous fiber reinforced artificial prosthesis as described in any one of claims 1-5.

Images