Integrated design method of macro-micro structure of skull patch with bionic vibration isolation function

Abstract

The application provides a skull patch macro-micro structure integrated design method with a bionic vibration isolation function, comprising the following steps: reconstructing a skull three-dimensional model based on CT data; designing a geometric shape of a skull patch according to a defect area in the skull three-dimensional model; establishing a finite element analysis model, and designing an overall structure of the skull patch based on a topological optimization method to obtain an overall truss structure of the skull patch and through holes between the truss structures; filling the through holes between the truss structures with a bionic vibration isolation structure; and filling the bionic vibration isolation structure with a lattice structure to obtain a skull patch macro-micro structure with a bionic vibration isolation function. The skull patch designed in the application has good vibration isolation function after being implanted in the body, thereby protecting internal brain tissues.

Description

Technical Field

[0001] The present invention relates to the technical field of medical devices, and in particular to a method for integrating macro- and micro-structure design of a skull patch with bionic vibration isolation function. Background Art

[0002] The skull is a vital bony structure in the human body. When damaged or missing, patients may face issues such as exposure of the brain to the external environment, imbalanced intracranial pressure, and aesthetic problems. Therefore, the integrity of the skull is of paramount importance. However, in cases such as trauma, tumor resection, congenital defects, infection, or decompressive craniectomy, the skull may be partially or completely lost. In these cases, doctors often perform cranioplasty to restore the integrity of the skull by implanting a skull patch. Skull patches not only restore the structure and function of the skull, protect the soft tissues of the brain, avoid the risk of trauma and infection, and improve head metabolism and neurological function; they also improve the appearance of the patient's head, reduce psychological burden, and enhance their quality of life.

[0003] Skull patch materials typically include autologous bone, allogeneic bone, and synthetic materials. Although autologous bone has good biocompatibility, it has many limitations on bone shape and size and may adversely affect the bone harvesting site. Homologous and xenogeneic bone are increasingly used due to the high risk of infection, rejection, and resorption. Existing skull patches are mostly made of engineering materials that combine excellent biocompatibility and mechanical strength, such as the most widely used titanium alloys and polyetheretherketone (PEEK).

[0004] However, titanium alloys and polyetheretherketone still have some disadvantages in practical applications. Titanium alloy, as a metal material, will produce artifacts during CT and MRI imaging, affecting the clarity and accuracy of postoperative imaging examinations; in addition, titanium alloy has strong thermal conductivity, which can easily cause patient discomfort when the ambient temperature changes. PEEK, as a polymer material, has an elastic modulus closer to that of bone, does not produce artifacts during imaging, and makes up for the disadvantages of titanium alloy in thermal conductivity. However, due to the lack of biomechanical analysis of PEEK patches in existing designs, PEEK patches lack the design of lattice structures in macro and micro structures compared to titanium alloy patches, resulting in a larger volume, and poor bone integration ability and soft tissue adhesion to the patch, leading to the formation of subcutaneous fluid accumulation. At the same time, due to the high crystallinity of PEEK material, during the fused deposition modeling (FDM) printing process, the newly deposited layer will cool and shrink rapidly, resulting in residual stress and warping.

[0005] Existing skull patch designs lack consideration for vibration isolation, yet one of the skull's primary functions is to protect the brain from external shock and vibration. Therefore, to restore the skull's vibration isolation function when filling a skull defect, reduce the impact of external vibration on brain tissue, and better protect patients from the risks of external physical vibration after surgery, skull patches should possess a certain degree of vibration isolation.

[0006] In summary, optimizing the macrostructure of the skull patch while maintaining strength and structural integrity, realizing the design of a vibration-isolating lattice structure in the microstructure, improving the growth and fusion ability of the skull patch with the skull and soft tissue, and using materials with higher printing controllability to manufacture the skull patch have become issues that need to be urgently addressed. Summary of the Invention

[0007] In view of this, the present invention provides a method for integrated macro-microstructure design of a skull patch with bionic vibration isolation function to solve the above problems.

[0008] The present invention provides an integrated design method for a skull patch macro-microstructure with a bionic vibration isolation function, comprising: reconstructing a three-dimensional skull model based on CT data; designing the geometric shape of the skull patch according to the defect area in the three-dimensional skull model; establishing a finite element analysis model, and designing the overall structure of the skull patch based on a topological optimization method to obtain an overall truss structure of the skull patch and through holes between the truss structures; filling the through holes between the truss structures with a bionic vibration isolation structure; and filling the bionic vibration isolation structure with a lattice structure to obtain a skull patch macro-microstructure with a bionic vibration isolation function.

[0009] Another aspect of the present invention also includes: with the goal of minimizing the strain energy of the skull patch, and with the volume fraction of the optimized skull patch volume relative to the original skull patch volume as a constraint condition, the skull patch is lightweight designed; the overall truss structure formed by the optimized skull patch is distributed along the direction of the load transfer force line of the skull patch, and through holes are formed between the truss structures.

[0010] In another aspect of the present invention, the volume fraction of the optimized skull patch volume relative to the original patch volume is between 50% and 90%.

[0011] In another aspect of the present invention, the minimum width of the overall truss structure is between 10 and 30 mm; and the distance between the through holes between the truss structures and the edge of the skull patch is between 10 and 15 mm.

[0012] In another aspect of the present invention, the bionic vibration isolation structure is a polygonal hole, which includes one or more regular polygons or irregular polygons, with a side length between 5 and 15 mm and a minimum distance between the sides between 2 and 5 mm.

[0013] In another aspect of the present invention, the aperture of the lattice structure is between 600 and 1000 μm; the wire diameter of the lattice structure is adjusted according to the printing capacity and is greater than 0.1 mm.

[0014] Another aspect of the present invention also includes: exporting the macro-microstructure of the skull patch with bionic vibration isolation function in a stereolithography format; according to the file in the stereolithography format, using polyetherketoneketone as the raw material, using fused deposition molding or powder bed-based laser selective sintering process to manufacture, to obtain a skull patch with bionic vibration isolation function.

[0015] Another aspect of the present invention further includes: the skull patch is implanted using an embedded method, and screws or connecting pieces are used to connect the skull patch to the surrounding corresponding bone tissue.

[0016] In the macro-microstructure integrated design method of a skull patch with bionic vibration isolation function of the present invention, the designed skull patch has a bionic vibration isolation structure. By imitating the vein arrangement of the wings of a bionic dragonfly, polygonal holes with vibration isolation effect are designed to effectively reduce the impact of external vibration on intracranial tissues; the skull patch can provide better shock absorption and protection when subjected to external impact or daily activities, reduce the impact on the brain, help improve postoperative comfort and safety, and reduce the risk of postoperative complications; at the same time, the use of macro-microstructure integrated design can ensure sufficient mechanical strength in the macrostructure, achieve lightweight design, and protect the internal tissues of the skull; the design of the microstructure promotes the integration of the skull and soft tissue with the skull patch, which helps shorten the patient's recovery time. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] To more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. By reading the detailed description of the embodiments below, the advantages and benefits of the solutions will become clear to those skilled in the art. The drawings are only for the purpose of illustrating preferred embodiments and are not to be considered as limiting the present invention.

[0018] In the attached figure:

[0019] Figure 1 This is a flow chart of a method for integrated macro- and micro-structure design of a skull patch with bionic vibration isolation function according to an embodiment of the present invention.

[0020] Figure 2 FIG. 1 is a schematic diagram of a skull patch in steps S102 to S104 according to an embodiment of the present invention.

[0021] Figure 3 Schematic diagram of the lattice structure design of one embodiment of the present invention.

[0022] Figure 4 This is a schematic diagram of embodiment 1 of the present invention.

[0023] Figure 5 This is a schematic diagram of embodiment 2 of the present invention. DETAILED DESCRIPTION

[0024] In order to enable those skilled in the art to better understand the technical solutions in the embodiments of the present invention, the technical solutions in the embodiments of the present invention will be clearly and detailedly described below in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. All other embodiments obtained by those skilled in the art based on the embodiments in the embodiments of the present invention should fall within the scope of protection of the embodiments of the present invention.

[0025] Figure 1 A schematic flow chart of a method for integrated macro-microstructure design of a skull patch with bionic vibration isolation function provided by an embodiment of the present invention is shown in FIG. Figure 1 As shown, this embodiment mainly includes the following steps:

[0026] S101. Reconstruct a three-dimensional skull model based on CT data.

[0027] S102. Designing the geometric shape of the skull patch according to the defect area in the three-dimensional skull model.

[0028] For example, Figure 2 As shown, the thickness of the skull patch is between 2 and 5 mm, and it has inner and outer curved surfaces with physiological curvature. The curvature of the surface is between 0 and 180 degrees, and the edge of the skull patch fits well with the defect area.

[0029] S103. Establish a finite element analysis model, design the overall structure of the skull patch based on a topology optimization method, and obtain the overall truss structure of the skull patch and the through holes between the truss structures.

[0030] For example, the topology optimization design method comprehensively considers the stress conditions of the skull under various working conditions, such as intracranial pressure, impact loads in different directions, etc.

[0031] S104: Fill the through holes between the truss structures using a bionic vibration isolation structure.

[0032] S105. Filling the bionic vibration isolation structure with the lattice structure to obtain a skull patch macro-microstructure with bionic vibration isolation function.

[0033] For example, when the polygonal hole is filled with the lattice structure, an interval filling method or a complete filling method may be adopted. The lattice structure completely fills the polygonal hole, that is, it occupies the entire internal space of the polygonal hole.

[0034] In the macro-microstructure integrated design method of a skull patch with bionic vibration isolation function of the present invention, the designed skull patch has a bionic vibration isolation structure. By imitating the vein arrangement of the wings of a bionic dragonfly, polygonal holes with vibration isolation effect are designed to effectively reduce the impact of external vibration on intracranial tissues; the skull patch can provide better shock absorption and protection when subjected to external impact or daily activities, reduce the impact on the brain, help improve postoperative comfort and safety, and reduce the risk of postoperative complications; at the same time, the use of macro-microstructure integrated design can ensure sufficient mechanical strength in the macrostructure, achieve lightweight design, and protect the internal tissues of the skull; the design of the microstructure promotes the integration of the skull and soft tissue with the skull patch, which helps shorten the patient's recovery time.

[0035] Another aspect of the present invention also includes: with the goal of minimizing the strain energy of the skull patch, and with the volume fraction of the optimized skull patch volume relative to the original skull patch volume as a constraint condition, the skull patch is lightweight designed; the overall truss structure formed by the optimized skull patch is distributed along the direction of the load transfer force line of the skull patch, and through holes are formed between the truss structures.

[0036] In another aspect of the present invention, the volume fraction of the optimized skull patch volume relative to the original patch volume is between 50% and 90%.

[0037] In another aspect of the present invention, the minimum width of the overall truss structure is between 10 and 30 mm; and the distance between the through holes between the truss structures and the edge of the skull patch is between 10 and 15 mm.

[0038] In another aspect of the present invention, the bionic vibration isolation structure is a polygonal hole, which includes one or more regular polygons or irregular polygons, with a side length between 5 and 15 mm and a minimum distance between the sides between 2 and 5 mm.

[0039] For example, regular polygons include quadrilaterals, pentagons, hexagons, and the like.

[0040] In another aspect of the present invention, the pore size of the lattice structure is between 600 and 1000 μm; the wire diameter of the lattice structure is adjusted according to the printing capacity and is greater than 0.1 mm.

[0041] Preferably, if Figure 3As shown, the microscopic lattice structure can be defined and changed according to size requirements and strength requirements. The lattice structure includes but is not limited to a three-dimensional periodic minimum surface structure, such as a Gyroid structure, a crystal structure, including a simple cubic structure, a body-centered cubic structure, a face-centered cubic structure, a complex geometric structure, including a diamond structure, a fluorite structure, and a Wilferlan structure, a polyhedral structure, including a truncated cube and a truncated octahedron, a honeycomb structure, and a truss structure, including an equiaxed truss structure, an octahedral truss structure, a back-entry structure, and a Voronoi filling structure.

[0042] Among them, the length and width of the three-dimensional periodic minimum surface structure unit are between 600 and 3000 μm, the height is between 2 and 15 mm, and the wire diameter is between 0.4 and 1.4 mm.

[0043] The point spacing of the Voronoi filling structure unit is between 0.6 and 5 mm, and the wire diameter is between 0.3 and 1 mm.

[0044] The length and width of other structural units are between 0.6 and 10 mm, the height is between 1 and 5 mm, and the wire diameter is between 0.5 and 1.5 mm.

[0045] Another aspect of the present invention also includes: exporting the macro-microstructure of the skull patch with bionic vibration isolation function in a stereolithography format; according to the stereolithography format (.STL) file, using polyetherketoneketone as the raw material, using fused deposition modeling or powder bed-based laser selective sintering process to manufacture, to obtain a skull patch with bionic vibration isolation function.

[0046] Preferably, polyetherketoneketone (PEKK) and PEEK belong to the same class of polyaryletherketone materials and have the advantages and characteristics of PEEK materials; however, the crystallinity of PEKK is lower than that of PEEK, and the crystallization speed is slower during the printing process, and the printing is more uniform, thus having better interlayer bonding strength, and there is no obvious anisotropy in the Y and Z directions caused by printing stacking.

[0047] The present invention is made of polyetherketoneketone material, which provides the patch with excellent mechanical properties and biocompatibility; the elastic modulus is similar to that of bone tissue, which can reduce the stress shielding effect and promote the natural growth and healing of bone tissue; it makes up for the disadvantages of titanium alloy material patches with high thermal conductivity and the presence of artifacts in medical imaging, and compared with polyetheretherketone of the same family, it has stronger interlayer bonding during FDM printing and is not prone to warping during the printing process, thereby improving the controllability of the printing process and the quality of the printed parts; it is integrated into a 3D printing mold and can directly produce complex geometric shapes without the need for additional processing or assembly, ensuring that the patch fits perfectly with the patient's skull and reducing production cycle and cost.

[0048] Another aspect of the present invention further includes: the skull patch is implanted using an embedded method, and screws or connecting pieces are used to connect the skull patch to the surrounding corresponding bone tissue.

[0049] Example 1, as Figure 4 As shown:

[0050] S1. The patient's skull defect was located in the frontal bone. A 3D skull model was reconstructed based on CT data. The skull patch was designed at the defect location, ensuring a good fit between the patch edge and the defect. The designed patch was 3mm thick and had internal and external curved surfaces with physiological curvature, ranging from 0 to 180°.

[0051] S2. A finite element analysis model was constructed for the forehead portion of the skull and the skull patch to simulate the stresses on the skull patch under intracranial pressure or impact loads. The patch's macrostructure was optimized to minimize strain energy, ensuring that the optimized skull patch volume was 80% of the original patch's volume fraction. A truss structure was formed, distributed along the load transmission lines acting on the skull patch, with through-holes formed between the trusses. The minimum width of the truss structure was 15.6 mm, and the through-holes were 10.6 mm from the edge of the skull patch.

[0052] S3. Use pentagonal holes to fill the through holes between the truss structures so that the skull patch has a bionic vibration isolation function. The side length of the pentagon is 5.8 mm, and the minimum spacing between the pentagons is 2 mm.

[0053] S4. Use a face-centered cubic lattice structure to fill the above-mentioned through-hole area; the length, width, and height of the structural unit are 3 mm respectively, and the wire diameter is 0.5 mm, so that the skull patch can better integrate with the surrounding bones and soft tissues after implantation.

[0054] The integrated macro- and micro-structure design of a skull patch with bionic vibration isolation function was completed. The design file was exported in .STL format, and polyetherketoneketone was used as the raw material. The skull patch was manufactured using the fused deposition modeling 3D printing process. The skull patch was implanted into the corresponding position using an embedded method, and connected to the surrounding bone tissue using connecting plates.

[0055] Example 2, as Figure 5 As shown:

[0056] S1. The patient's skull defect is located in the upper parietal bone. A 3D skull model was reconstructed based on CT data. The skull patch was designed at the defect location, ensuring a good fit between the patch edge and the defect. The designed patch was 3mm thick and had internal and external curved surfaces with physiological curvature, ranging from 0 to 180°.

[0057] S2. A finite element analysis model was constructed for the parietal bone and skull patch above the skull to simulate the stresses on the skull patch under intracranial pressure or impact loads. The patch's macrostructure was optimized to minimize strain energy, ensuring that the optimized skull patch volume was 70% of the original patch's volume fraction. A truss structure was formed, distributed along the load transmission lines acting on the skull patch, with through-holes formed between the trusses. The minimum width of the truss structure was 10.8 mm, and the through-holes were 10 mm from the edge of the skull patch.

[0058] S3. Fill the through holes between the truss structures with hexagonal holes to provide the skull patch with bionic vibration isolation. The side length of the hexagon is 5 mm, and the minimum spacing between the hexagons is 2 mm.

[0059] S4. Use the Voronoi lattice structure to fill the above-mentioned through-hole area; the point spacing of the structural unit is 1.5 mm, and the wire diameter is 0.5 mm, so that the skull patch can better integrate with the surrounding bones and soft tissues after implantation.

[0060] The integrated macro- and micro-structure design of a skull patch with bionic vibration isolation function was completed. The design file was exported in .STL format. Polyetherketoneketone was used as the raw material and manufactured using a powder bed-based laser selective sintering process. The skull patch was implanted in the corresponding position using an embedded method and connected to the surrounding bone tissue using screws.

[0061] The skull patch designed by the present invention has the characteristics of personalization, integration and lightweight while ensuring mechanical properties; after being implanted in the body, the designed skull patch has good vibration isolation function, thereby protecting the internal tissues of the brain; it can better integrate with autologous bone and soft tissue, thereby achieving the effect of reducing the occurrence of subcutaneous effusion; the manufacturing process is simpler, and the PEKK material makes the 3D printed patch shape more precise and controllable, and the patch has better interlayer bonding strength.

[0062] In another aspect of the present invention, an electronic device includes a processor, a memory, a communication bus, and a communication interface.

[0063] in:

[0064] The processor, memory and communication interface communicate with each other through a communication bus.

[0065] Communication interface, used to communicate with other electronic devices or servers.

[0066] The processor is configured to execute a program, and specifically, execute the steps of any one of the above-mentioned methods for designing a macro-micro structure integrated cranioplasty patch with a bionic vibration isolation function.

[0067] Specifically, the program can include program code including computer operation instructions.

[0068] The processor can be a central processing unit (CPU), or an application specific integrated circuit (ASIC), or one or more integrated circuits configured to implement the embodiments of the present application. The one or more processors included in the smart device can be processors of the same type, such as one or more CPUs, or processors of different types, such as one or more CPUs and one or more ASICs.

[0069] The memory is configured to store the program. The memory can include a high-speed RAM memory, and can also include a non-volatile memory, such as at least one disk memory.

[0070] The program can be specifically configured to cause the processor to execute to implement the steps of any one of the methods for designing a macro-micro structure integrated cranioplasty patch with a bionic vibration isolation function described in the embodiments. The specific implementation of each step in the program can refer to the corresponding description of the steps and units executed by any one of the above-mentioned methods for designing a macro-micro structure integrated cranioplasty patch with a bionic vibration isolation function, which will not be described here. Those skilled in the art can clearly understand that, for the convenience and brevity of description, the specific working processes of the above-mentioned devices and modules can refer to the corresponding process descriptions in the foregoing method embodiments.

[0071] The exemplary embodiments of the present application also provide a non-transitory computer-readable storage medium storing computer instructions, wherein the computer instructions are configured to cause a computer to execute the method of any one of the embodiments of the present application.

[0072] The method according to the embodiment of the present invention described above can be implemented in hardware, firmware, or as software or computer code that can be stored in a recording medium (such as a CD ROM, RAM, floppy disk, hard disk or magneto-optical disk), or as computer code that is originally stored in a remote recording medium or a non-temporary machine-readable medium downloaded via a network and will be stored in a local recording medium, so that the method described herein can be stored in such software processing on a recording medium using a general-purpose computer, a dedicated processor or programmable or dedicated hardware (such as an ASIC or FPGA). It can be understood that a computer, a processor, a microprocessor controller or programmable hardware includes a storage component (e.g., RAM, ROM, flash memory, etc.) that can store or receive software or computer code, and when the software or computer code is accessed and executed by a computer, a processor or hardware, the method described herein is implemented. In addition, when a general-purpose computer accesses the code for implementing the method shown here, the execution of the code converts the general-purpose computer into a dedicated computer for executing the method shown here.

[0073] Thus far, specific embodiments of the present invention have been described. Other embodiments are within the scope of the appended claims. In some cases, the actions recited in the claims can be performed in a different order and still achieve the desired results. Furthermore, the processes depicted in the accompanying drawings do not necessarily require the specific order shown or sequential order to achieve the desired results. In certain embodiments, multitasking and parallel processing may be advantageous.

[0074] It should be noted that all directional indications in the embodiments of the present invention (such as up, down, left, right, back, etc.) are only used to explain the relative position relationship, movement status, etc. between the various components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.

[0075] In the description of the present invention, the terms "first" and "second" are used solely to facilitate description of different components or names and should not be construed as indicating or implying a sequential relationship, relative importance, or implicitly specifying the quantity of the technical features being described. Therefore, features specified as "first" or "second" may explicitly or implicitly include at least one of such features.

[0076] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art of the present invention. The terms used in this specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention.

[0077] It should be noted that although the specific embodiments of the present invention are described in detail in conjunction with the accompanying drawings, this should not be construed as limiting the scope of protection of the present invention. Within the scope described by the claims, various modifications and variations that can be made by those skilled in the art without creative effort still fall within the scope of protection of the present invention.

[0078] The examples of the embodiments of the present invention are intended to briefly illustrate the technical features of the embodiments of the present invention so that those skilled in the art can intuitively understand the technical features of the embodiments of the present invention, and are not intended to improperly limit the embodiments of the present invention.

[0079] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the present invention.

Claims

1. A method for integrated macro-microstructure design of a skull patch with bionic vibration isolation function, characterized in that: include: Reconstruct a three-dimensional skull model based on CT data; designing the geometric shape of the skull patch according to the defect area in the three-dimensional skull model; A finite element analysis model is established to simulate the stress conditions of the skull patch under conditions of intracranial pressure or impact load; with the goal of minimizing the strain energy of the skull patch and the volume fraction of the optimized skull patch relative to the original skull patch volume as a constraint, the skull patch is lightweight designed; the overall structure of the skull patch is designed based on a topological optimization method to obtain an overall truss structure of the skull patch and through holes between the truss structures; the overall truss structure formed by the optimized skull patch is distributed along the direction of the load transmission force line of the skull patch, and through holes are formed between the truss structures; Filling the through holes between the truss structures with a bionic vibration isolation structure; The bionic vibration isolation structure is filled with a lattice structure to obtain a skull patch macro-microstructure with bionic vibration isolation function; Exporting the macro-microstructure of the skull patch with bionic vibration isolation function in a stereolithography format; According to the stereolithography format file, polyetherketoneketone is used as the raw material and manufactured using fused deposition modeling or powder bed-based laser selective sintering process to obtain a skull patch with bionic vibration isolation function.

2. The method according to claim 1, characterized in that The volume fraction of the optimized skull patch volume relative to the original skull patch volume is between 50% and 90%.

3. The method according to claim 1, characterized in that The minimum width of the overall truss structure is between 10 and 30 mm; The through holes between the truss structures are located 10 to 15 mm away from the edge of the skull patch.

4. The method according to claim 1, wherein The bionic vibration isolation structure is a polygonal hole, which includes one or more regular polygons or irregular polygons, with a side length between 5 and 15 mm and a minimum distance between the sides between 2 and 5 mm.

5. The method according to claim 1, wherein The pore size of the lattice structure is between 600 and 1000 μm; The wire diameter of the lattice structure is adjusted according to the printing capacity and is greater than 0.1 mm.

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