Modular bionic training model and preparation method thereof

Abstract

The application provides a modular bionic training model and a preparation method thereof. The preparation method of the gradient cross-linked modular bionic training model comprises the following steps: determining a plurality of human tissue modules corresponding to the modular bionic training model to be simulated; preparing a bionic solution corresponding to each human tissue module by using a predetermined hydrophilic polymer material; providing a mold corresponding to each human tissue module, and injecting each bionic solution into the corresponding mold; performing freeze-thaw circulation on each mold into which the bionic solution is injected, to obtain a plurality of bionic tissue modules with different cross-linking degrees; mounting the plurality of bionic tissue modules on corresponding mounting positions of a predetermined base body, to obtain a pre-assembled body; and pouring a mucosa layer on the pre-assembled body, to obtain the modular bionic training model. The application prepares a plurality of bionic tissue modules with different cross-linking degrees, and then obtains a modular bionic training model close to reality, so that the simulation degree of the bionic training model is improved.

Description

Technical Field

[0001] This invention relates to the field of medical device technology, and in particular to a modular biomimetic training model and its preparation method. Background Technology

[0002] Bionic training models (also known as simulators) are realistic physical models that replicate the actual anatomical structure, tissue mechanics, and cavity environment of the human body. For example, functional sinus endotomy (FESS) is a core procedure in otolaryngology, requiring extremely high levels of anatomical recognition and operational precision. Current physician skills training suffers from limitations in biological specimen access (such as ethical restrictions on cadaver dissection), non-reusability, and the risk of infectious diseases. Therefore, bionic training models are needed for physician practice, instrument testing, and other purposes.

[0003] However, existing biomimetic training models all have shortcomings. For example, VR simulators can only provide visual feedback, lacking tactile feedback; silicone models are homogeneous single-layer structures without bony support, making them unable to simulate resection / dissection operations; the hardness of 3D-printed resin differs greatly from human tissue, limiting its use to teaching purposes; and existing organoid printing technology is only suitable for solid soft tissue, unable to replicate the complex structure of sinus bony cavities, mucosa, and cartilage. In short, existing biomimetic training models have low simulation accuracy.

[0004] Therefore, existing technologies have shortcomings and need to be improved and developed. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to provide a modular biomimetic training model and its preparation method, which addresses the above-mentioned defects of the prior art and aims to solve the problem of low simulation degree of biomimetic training models in the prior art.

[0006] The technical solution adopted by this invention to solve the technical problem is as follows: A method for preparing a gradient cross-linked modular biomimetic training model, the method comprising: Multiple human tissue modules corresponding to the modular biomimetic training model to be simulated were identified, and biomimetic solutions corresponding to each human tissue module were prepared using predetermined hydrophilic polymer materials. Provide molds corresponding to each human tissue module, and inject each biomimetic solution into the corresponding mold respectively; By performing freeze-thaw cycles on each mold that has been injected with biomimetic solution, multiple biomimetic tissue modules with different degrees of cross-linking were obtained. Multiple biomimetic tissue modules are respectively installed in the corresponding mounting positions of a predetermined substrate to obtain a pre-assembled body; A mucosa layer is poured onto the pre-assembled body to obtain a modular biomimetic training model.

[0007] In one embodiment of this application, multiple human tissue modules corresponding to the modular biomimetic training model to be simulated are determined, and biomimetic solutions corresponding to each human tissue module are prepared using a predetermined hydrophilic polymer material, including: The modular biomimetic training model to be simulated is identified by determining multiple human tissue modules, the mechanical parameters of different human tissue modules are determined, and the cross-linking degree gradient is determined based on the mechanical parameters. Based on the crosslinking degree gradient, the required ratio of hydrophilic polymer materials and the number of freeze-thaw cycles for the biomimetic solution corresponding to each human tissue module are set. Based on the predetermined ratio of hydrophilic polymer materials, biomimetic solutions corresponding to each human tissue module were prepared.

[0008] In one embodiment of this application, each mold injected with a biomimetic solution undergoes a freeze-thaw cycle to obtain multiple biomimetic tissue modules with different degrees of crosslinking, including: Based on the number of freeze-thaw cycles corresponding to each human tissue module, freeze-thaw cycles were performed on each mold that had been injected with biomimetic solution to obtain multiple biomimetic tissue modules with different degrees of cross-linking.

[0009] In one embodiment of this application, a mucosal layer is cast onto the pre-assembled body to obtain a modular biomimetic training model, including: An outer mold is provided, the pre-assembled body is placed in the outer mold, and there is a mucous membrane layer space between the pre-assembled body and the outer mold; A hydrophilic polymer solution of predetermined concentration is injected through the inlet hole of the outer mold. After the outer mold filled with hydrophilic polymer solution is subjected to freeze-thaw cycles, it is demolded to obtain a modular biomimetic training model with a mucous membrane layer.

[0010] In one embodiment of this application, the modular bionic training model is a functional sinus surgery training model; after casting the mucosal layer onto the pre-assembled body to obtain the modular bionic training model, the method further includes: A predetermined coating solution is prepared and uniformly sprayed onto the surface of the modular biomimetic training model to simulate the nasal mucus layer. The modular bionic training model was placed in a sealed, moisturizing box, and glycerol phosphate buffer was sprayed onto the surface of the functional sinus surgery training model. The model was then equilibrated at a predetermined temperature for a predetermined duration to allow the mucosal layer to swell and stabilize.

[0011] In one embodiment of this application, after casting a mucosal layer onto the pre-assembled body to obtain a modular biomimetic training model, the method further includes: Obtain the predetermined test items corresponding to the modular bionic training model, test the modular bionic training model based on each predetermined test item, and obtain the results of each test item. If the results of each test item meet the predetermined qualification standard, the modular bionic training model is successfully prepared.

[0012] In one embodiment of this application, the predetermined hydrophilic polymeric material includes at least one of polyvinyl alcohol, gelatin, and sodium alginate.

[0013] This application also provides a gradient crosslinked modular biomimetic training model, comprising: a substrate and multiple biomimetic tissue modules; the multiple biomimetic tissue modules are respectively formed and installed at corresponding mounting positions on the substrate, and form a pre-assembled body according to the position of the human tissue to be simulated; the biomimetic tissue modules in the pre-assembled body are covered with a mucosal layer; each of the biomimetic tissue modules has a different degree of crosslinking, and at least one of the multiple biomimetic tissue modules is installed on the substrate in a way that allows for independent replacement.

[0014] In one embodiment of this application, the modular bionic training model is a functional sinus surgery training model; the plurality of bionic tissue modules include skull base and anterior sphenoid sinus wall components, uncinate process components, ethmoid bulla components, paper template components, middle turbinate components, and maxillary sinus ostium ring components.

[0015] In one embodiment of this application, the plurality of biomimetic tissue modules are divided into one-time replacement modules, reusable modules, and permanent modules according to the wear frequency during the training process; the one-time replacement module, the reusable module, and the permanent module are each independently formed and installed in the corresponding mounting position of the substrate.

[0016] This invention provides a modular biomimetic training model and its preparation method. The preparation method of the gradient cross-linked modular biomimetic training model includes: determining multiple human tissue modules corresponding to the modular biomimetic training model to be simulated; preparing biomimetic solutions corresponding to each human tissue module using a predetermined hydrophilic polymer material; providing molds corresponding to each human tissue module; injecting each biomimetic solution into the corresponding mold; performing freeze-thaw cycles on each mold with injected biomimetic solution to obtain multiple biomimetic tissue modules with different degrees of cross-linking; installing the multiple biomimetic tissue modules onto corresponding mounting positions on a predetermined substrate to obtain a pre-assembled body; and casting a mucosal layer onto the pre-assembled body to obtain the modular biomimetic training model. This application improves the simulation accuracy of the biomimetic training model by dividing the biomimetic training model into multiple human tissue modules and preparing multiple biomimetic tissue modules with different degrees of cross-linking. Attached Figure Description

[0017] Figure 1 This is a flowchart of a preferred embodiment of the method for preparing a gradient cross-linked modular biomimetic training model in this invention.

[0018] Figure 2This is a schematic diagram of the skull model in this invention.

[0019] Figure 3 This is a schematic diagram of facial skin in this invention.

[0020] Figure 4 This is a schematic diagram of the nasal cavity simulation component in this invention. Detailed Implementation

[0021] To make the objectives, technical solutions, and advantages of this invention clearer and more explicit, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

[0022] Existing simulators have significant drawbacks: VR simulators can only provide visual feedback and have no tactile feedback, with a single unit costing over 500,000 yuan; silicone models have a homogeneous single-layer structure, lacking bony support and unable to simulate resection / dissection operations; the hardness of 3D printing resin differs greatly from that of human tissue, and can only be used for teaching purposes; existing organoid printing technology is only suitable for solid soft tissue and cannot reproduce the complex structure of sinus sinus "bony cavity, mucosa, and cartilage".

[0023] Furthermore, there is a mismatch between training costs and efficiency. Novice doctors lack opportunities for low-risk hands-on practice, resulting in a high incidence of intraoperative complications. There is an urgent need for low-cost, highly realistic, and reusable training platforms.

[0024] In summary, existing biomimetic training models suffer from low simulation fidelity, poor reusability, and high cost. To address these shortcomings, this invention proposes a three-pronged solution integrating biomimetic materials, layered structures, and modular lifespan management.

[0025] The following description, with reference to the accompanying drawings, illustrates an embodiment of a modular biomimetic training model and its preparation method. Addressing the low simulation fidelity of biomimetic training models in the related technologies mentioned in the background section, this application provides a method for preparing a gradient-crosslinked modular biomimetic training model. In this method, multiple human tissue modules corresponding to the modular biomimetic training model to be simulated are determined; biomimetic solutions corresponding to each human tissue module are prepared using a predetermined hydrophilic polymer material; molds corresponding to each human tissue module are provided, and each biomimetic solution is injected into its corresponding mold; freeze-thaw cycles are performed on each mold containing the biomimetic solution to obtain multiple biomimetic tissue modules with different degrees of crosslinking; the multiple biomimetic tissue modules are respectively installed at corresponding mounting positions on a predetermined substrate to obtain a pre-assembled body; a mucosal layer is cast onto the pre-assembled body to obtain the modular biomimetic training model. This application, by dividing the biomimetic training model into multiple human tissue modules and preparing multiple biomimetic tissue modules with different degrees of crosslinking, obtains a modular biomimetic training model with near-realistic simulation, thereby improving the simulation fidelity of the biomimetic training model.

[0026] Please see Figure 1 , Figure 1 This is a flowchart illustrating the preparation method of the gradient cross-linked modular biomimetic training model in this invention. For example... Figure 1 As shown, the method for preparing the gradient cross-linked modular biomimetic training model according to the embodiments of the present invention includes: Step S100: Determine the multiple human tissue modules corresponding to the modular biomimetic training model to be simulated, and prepare biomimetic solutions corresponding to each human tissue module using predetermined hydrophilic polymer materials.

[0027] For example, the predetermined hydrophilic polymer material can be PVA (polyvinyl alcohol). Using different proportions of polyvinyl alcohol can yield PVA hydrogels with different proportions to simulate different tissue mechanical properties. PVA hydrogel is a water-containing solid flexible colloidal material formed by dispersing water molecules within the three-dimensional network structure of polyvinyl alcohol polymer as the matrix.

[0028] In one embodiment, a predetermined relationship between the ratio of hydrophilic polymer materials and the degree of crosslinking can be set in advance. Then, based on the required degree of crosslinking for different human tissue modules, the required ratio can be determined to prepare the corresponding biomimetic solution. This application uses low-crosslinked PVA hydrogels to simulate mucous membranes, polyps, etc., and medium-crosslinked PVA hydrogels to simulate cartilage and bone structures. The transparency of the PVA hydrogels supports real-time endoscopic observation of the operating depth.

[0029] The human tissue module prepared based on a predetermined hydrophilic polymer material in this application is closer to the feel of real surgery.

[0030] In this embodiment of the application, step S100 specifically includes: Step S110: Determine multiple human tissue modules corresponding to the modular bionic training model to be simulated, determine the mechanical parameters of different human tissue modules, and determine the cross-linking gradient based on the mechanical parameters. Step S120: Based on the cross-linking degree gradient, set the ratio of the predetermined hydrophilic polymer material and the number of freeze-thaw cycles required for the biomimetic solution corresponding to each human tissue module; Step S130: Prepare biomimetic solutions corresponding to each human tissue module according to the predetermined ratio of hydrophilic polymer materials.

[0031] For example, a cross-linking gradient is set according to the mechanical parameters of different tissues in the human nasal cavity.

[0032] This application utilizes multi-layered irrigation and different proportions of predetermined hydrophilic polymer materials (such as PVA) to create a multi-level structural design that simulates complex human structures (such as sinus structures), and can pre-embed capillaries and red glycerol water between layers to simulate bleeding.

[0033] like Figure 1 As shown, the method for preparing the gradient cross-linked modular biomimetic training model according to the embodiments of the present invention further includes: Step S200: Provide molds corresponding to each human tissue module, and inject each biomimetic solution into the corresponding mold.

[0034] like Figure 1 As shown in the embodiment of the present invention, the method for preparing the gradient cross-linked modular biomimetic training model further includes: Step S300: Perform freeze-thaw cycles on each mold that has been injected with biomimetic solution to obtain multiple biomimetic tissue modules with different degrees of cross-linking.

[0035] In this embodiment of the application, step S300 specifically includes: performing freeze-thaw cycles on each mold that has been injected with biomimetic solution based on the number of freeze-thaw cycles corresponding to each human tissue module, to obtain multiple biomimetic tissue modules with different degrees of crosslinking.

[0036] This application prepares multiple biomimetic tissue modules with different degrees of crosslinking by controlling the number of freeze-thaw cycles, thereby obtaining multiple biomimetic tissue modules with different mechanical properties.

[0037] like Figure 1 As shown, the method for preparing the gradient cross-linked modular biomimetic training model according to the embodiments of the present invention further includes: Step S400: Install multiple biomimetic tissue modules into the corresponding mounting positions of the predetermined substrate to obtain a pre-assembled body.

[0038] The base is a permanent base component, such as... Figure 2 As shown, the skull model serves as the substrate, made from photocurable resin using 3D printing technology. For example, 3D printing can be performed up to a week before the preparation of the modular biomimetic training model. This substrate is universal for all models and has a lifespan of 1-2 years.

[0039] like Figure 1 As shown in the embodiment of the present invention, the method for preparing the gradient cross-linked modular biomimetic training model further includes: Step S500: Cast a mucosa layer onto the pre-assembled body to obtain a modular biomimetic training model.

[0040] In this embodiment of the application, step S500 specifically includes: Step S510: Provide an outer mold, place the pre-assembled body into the outer mold, and there is a mucous membrane layer space between the pre-assembled body and the outer mold; Step S520: Inject a hydrophilic polymer material solution of a predetermined concentration into the inlet hole of the outer mold. After the outer mold filled with the hydrophilic polymer material solution is subjected to freeze-thaw cycles, it is demolded to obtain a modular biomimetic training model with a mucous membrane layer.

[0041] Specifically, the outer mold can be a silicone mold, preferably made of food-grade platinum silicone. The production cycle is 24 hours of molding, and it can be used 50-100 times. If the silicone outer mold shows cracks or damage exceeding 2 cm in length, the mold is considered faulty and must be discarded and replaced. Figure 3 As shown, the outer model can be a facial skin structure.

[0042] This application obtains a layered structure through external mold casting. The layered structure is a heterogeneous composite design, including a mucosal layer, a gap layer, and a bone / cartilage layer. It may also include warning and feedback pre-embedded structures corresponding to each layer, thereby realizing the function of independently replacing each module in the modular bionic training model.

[0043] In one embodiment of this application, the modular bionic training model is a functional sinus patency surgery training model; after step S500, the method further includes: preparing a predetermined coating solution, uniformly spraying the predetermined coating solution onto the surface of the modular bionic training model to simulate the nasal mucus layer; placing the modular bionic training model into a sealed moisturizing box, and spraying glycerol phosphate buffer onto the surface of the functional sinus patency surgery training model, balancing it at a predetermined temperature for a predetermined time to allow the mucosal layer to swell and stabilize.

[0044] Specifically, the intended coating solution is a 0.5% (w / v) aqueous solution of poloxamer 407, which is a triblock copolymer of polyethylene oxide, polypropylene oxide, and polyethylene oxide. Specifically, 0.5 g of poloxamer 407 solid powder is weighed and added to 100 mL of deionized water, and dissolved by stirring at room temperature. The solution is then poured into a spray bottle and sprayed evenly 2-3 times from a distance of 20 cm from the model surface. The coating should be thin and uniform, without forming droplets or drips.

[0045] This application achieves the effect of uniformly spraying a predetermined coating solution to simulate the slippery feel of the nasal mucus layer and reduce the coefficient of friction of the instrument.

[0046] In one embodiment of this application, after step S500, the method further includes: obtaining predetermined inspection items corresponding to the modular bionic training model; inspecting the modular bionic training model based on each predetermined inspection item to obtain the results of each inspection item; if the results of each inspection item all meet the predetermined qualification standard, the modular bionic training model is successfully prepared.

[0047] This application obtains a qualified modular bionic training model by testing the modular bionic training model.

[0048] In this embodiment of the application, the predetermined hydrophilic polymer material includes at least one of polyvinyl alcohol, gelatin, and sodium alginate.

[0049] This application also provides a gradient crosslinked modular biomimetic training model, comprising: a substrate and multiple biomimetic tissue modules; the multiple biomimetic tissue modules are respectively formed and installed at corresponding mounting positions on the substrate, and form a pre-assembled body according to the position of the human tissue to be simulated; the biomimetic tissue modules in the pre-assembled body are covered with a mucosal layer; each of the biomimetic tissue modules has a different degree of crosslinking, and at least one of the multiple biomimetic tissue modules is installed on the substrate in a way that allows for independent replacement.

[0050] This application supports the individual replacement of consumable parts according to training needs, reducing the overall cost of use by more than 60%.

[0051] In this embodiment, the modular bionic training model is a functional sinus surgery training model; the multiple bionic tissue modules include skull base and anterior sphenoid sinus wall components, uncinate process components, ethmoid bulla components, paper template components, middle turbinate components, and maxillary sinus ostium components.

[0052] This application achieves modularization of the training model for functional sinus surgery, thereby improving the simulation accuracy.

[0053] In one embodiment of this application, the plurality of biomimetic tissue modules are divided into one-time replacement modules, reusable modules, and permanent modules according to the wear frequency during the training process; the one-time replacement module, the reusable module, and the permanent module are each independently formed and installed in the corresponding mounting position of the substrate.

[0054] Specifically, this application designs a three-tiered component lifespan system: a disposable consumable layer (mucosa / lesion tissue), a reusable functional layer (bone / cartilage scaffold), and a permanent base layer (facial contour matrix). For example, Figure 2 skull model and Figure 3 All silicone outer molds are permanent base layers. Figure 4 The nasal cavity simulation component is made of PVA through freeze-thaw cross-linking and is a reusable functional layer, while the mucosal layer is a disposable consumable layer. Understandably, the three-level lifespan can be simplified to two levels.

[0055] The three-tiered lifespan system proposed in this application balances the versatility and durability of the training platform, reducing maintenance and replacement costs.

[0056] In addition, the biomimetic simulation and three-level lifespan system of this application can serve as the basis for various nasal and nasal skull base surgical models, thereby enabling the development of surgical models for sinusitis with nasal polyps, nasal septum deviation with + / - turbinate hypertrophy, nasal cavity / sinus tumors, nasal skull base surgical models, and nasopharyngeal tumor models.

[0057] In addition to the nasal cavity and sinus fields, this application can also be used for training models in pharyngeal, otological, and skull base surgeries, such as training models for laryngeal cancer resection under laryngoscopy and training models for cochlear implantation into the temporal bone. Only the PVA ratio and layered structure need to be adjusted, without changing the core design logic.

[0058] This application is compatible with individualized CT data of patients and can customize training modules to match specific anatomical structures. It also incorporates complication training mechanisms such as bleeding simulation, danger zone warning, and fracture biomechanical guidance, thereby achieving tactile and operational feedback close to that of real surgery. It fills the gap in highly realistic nasal endoscopy training models and is suitable for various scenarios such as standardized training and preoperative drills.

[0059] The following are specific examples for illustration.

[0060] Example 1: The steps for preparing a training model for functional sinus surgery include: Step S1: Preparation of skull base and anterior sphenoid sinus components: The biomimetic solution is obtained by mixing a 20% (w / w) polyvinyl alcohol (PVA) aqueous solution with plaster powder, undergoing 10 freeze-thaw cycles. The solution is grayish-white in appearance and extremely hard. The construction period is approximately 7.5 days. The criteria for evaluation are: no indentation when pressed with a fingernail, and a white scratch when lightly scratched with a scalpel.

[0061] Step S1 specifically includes: Step S11, Weigh (accurate to 0.01 g): PVA powder: 12 g, gypsum powder: 6 g (sieved to remove lumps), deionized water: 48 mL, glycerin: 3 g.

[0062] Step S12, Swelling (30 min): Slowly sprinkle PVA powder into cold water while stirring to prevent clumping. Let stand for 30 min to allow the PVA to fully absorb water and swell. Observation: The powder should be evenly dispersed without any white floating clumps.

[0063] Step S13, Dissolving (2 h): Set the water bath to 90°C, place the beaker inside, and stir magnetically at 300 rpm. After 30 min, check: the solution should be a milky white suspension. After 1 h, check: the suspension becomes clear, but there are still a few undissolved particles. After 1.5 h: add gypsum powder and continue stirring for 30 min (gypsum does not dissolve and remains in a uniform suspension). After 2 h: the solution is completely clear, the gypsum is uniformly suspended, and there is no sediment or stratification. Judgment criteria: when dipped in a glass rod, the drop forms a continuous liquid flow without any grainy feel.

[0064] Step S14, Degassing (30 min): Pour into a vacuum drying oven and evacuate to 0.08 MPa. Observe the rising and bursting of bubbles, and the liquid level dropping by about 5%. Release the vacuum; if large bubbles are still present, repeat once.

[0065] Step S15, Color Adjustment: Add 0.05 g of gray food coloring and stir for 5 minutes until homogeneous. Color standard: light grayish-white, similar to the color of bone tissue.

[0066] Step S16, Casting: The mold is a 30×20×2 mm inclined frame (30° inclination). Mold pretreatment: Spray the inner wall with Vaseline release agent, and wipe away the excess with a lint-free cloth (leaving only a thin layer). Slowly pour in the solution, avoiding impact to prevent air bubbles. Vibration venting: Place the mold on a vibration table at a frequency of 50 Hz and an amplitude of 1 mm for 2 minutes. Smooth the surface until the liquid level is flush with the upper edge of the mold.

[0067] Step S17, freeze-thaw cycle 10 times (approximately 7.5 days): Each cycle: freeze at -20°C for 12 hours → thaw at 4°C for 6 hours. Key controls: Each freezing cycle must be at least 12 hours (refrigerator temperature display ≤ -18°C); each thawing cycle must be at least 6 hours (do not demold prematurely).

[0068] Step S18, Demolding and Inspection: After confirming complete thawing, gently push the ejector pin at the bottom of the mold to release the component. Inspection: The surface should be free of air bubbles, cracks, and have a uniform color. Hardness Test: Pressing with a fingernail should leave no indentation; a light scratch with a scalpel should leave a white mark (similar to plaster). Defective Product Marking: Surface air bubbles > φ2mm or through cracks → scrap and rework.

[0069] Step S19, Equilibrium Storage: Immerse in a 10% glycerol aqueous solution and store at 4°C. Label: "Skull base component / 20% PVA + plaster / 10 freeze-thaw cycles / Completed on D4".

[0070] Step S2: Preparation of the hook-shaped component: The biomimetic solution is 12% PVA by mass, with 5 freeze-thaw cycles. The appearance is pale yellow, 40mm × 8mm × 2mm, with longitudinal grooves. The production time is approximately 2.75 days. The judgment criteria are continuous and unbroken raised lines, and no breakage when bent at 90°.

[0071] Step S2 specifically includes: Step S21, Weighing (synchronized with the preparation steps of the skull base and anterior sphenoid sinus components): PVA: 6 g, glycerol: 2 g, deionized water: 40 mL.

[0072] Step S22, Swelling-Dissolving-Defoaming: Dissolution time is shortened to 1.5 h (low concentration, fast dissolution). Color adjustment: Add 0.02 g of yellow food coloring; color standard: pale yellow, similar to the color of periosteum.

[0073] Step S23, Mold Pre-treatment (Key Step): The mold is a 40mm × 8mm × 2mm rectangular silicone mold. Longitudinal Scribing: Three 0.3mm thick, 0.5mm wide nylon lines, 2mm apart, parallel to the long axis, are pasted onto the bottom surface of the mold (which will form the surface of the component after casting). Scribing Function: To simulate the longitudinal texture of the uncinate process bone fibers; during training, the peeler will move along the texture with a "sandy" feel.

[0074] Step S24, Pouring: Slowly pour in the solution, ensuring the liquid level is slightly above the upper edge of the mold (to compensate for shrinkage). Vibrate to release air for 2 minutes. Gently scrape the surface along the groove direction with a scraper to ensure the solution fully fills the grooves.

[0075] Step S25, freeze-thaw cycle 5 times (approximately 3.75 days): Each time: freeze at -20°C for 12 h → thaw at 4°C for 6 h.

[0076] Step S26, Demolding and Inspection: After demolding, three parallel raised lines are visible (corresponding to the markings on the bottom of the mold). Inspection: The raised lines are continuous without breakage, and the height is uniform (0.2~0.3 mm). Toughness Test: It does not break when bent at 90°, and there is no permanent deformation after springback. Cutting Test: When cut with a No. 11 scalpel, there is resistance but it can be cut through, and the cut surface is clean.

[0077] Step S3: Preparation of the sieve-bubble component (lost-wax method): The biomimetic solution is a 15% (w / w) polyvinyl alcohol (PVA) aqueous solution, with 6 freeze-thaw cycles. The sphere is φ12 mm in diameter, with a wall thickness of 2 mm, and contains 6 air cells. The production period is approximately 2.75 days, including the melt core. The judgment criteria are a "feeling of emptiness" before the front wall is removed, and honeycomb-like cavities are visible upon entering the air cells.

[0078] Step S3 specifically includes: Step S31: Pre-preparing the agar core material (start 1 day in advance or on the first morning): Dissolve 2g of agar powder in 100mL of deionized water by heating in an 85°C water bath until completely clear. Pour into spherical molds: 6 φ3mm spherical silicone molds per mold. Cool and solidify at room temperature for 30 minutes. Demolding: You will get 6 φ3mm agar balls / mold, a total of 10 molds are needed (4 sets are for backup). Storage: Sealed box, 4°C, to prevent dehydration.

[0079] Step S32, PVA solution preparation (simultaneous with the preparation of the skull base / uncinate process components): Weigh PVA: 5 g, glycerol: 2 g, deionized water: 30 mL. Swell for 30 min → dissolve at 90°C for 1.5 h → defoam for 30 min. Color adjustment: Add 0.02 g of blue food coloring. Color standard: light blue, to distinguish it from the yellow of the uncinate process and the pink of the middle turbinate.

[0080] Step S33, Casting and Core Embedding (Key Step): The mold is a spherical two-part mold with an outer diameter of φ12 mm and an inner cavity of φ8 mm (wall thickness of 2 mm).

[0081] Operation sequence: a. Place 6 agar balls evenly into the lower valve mold (distributed in a honeycomb pattern, with the center of the balls about 4 mm apart). b. Slowly pour in PVA solution until it submerges the top of the agar balls by 2 mm; c. Close the upper flap mold and gently press to expel excess solution; d. Secure the two mold halves with rubber bands to prevent leakage; e. Vibrate to release air for 3 minutes (air bubbles are easily trapped around the agar balls, so thorough air release is necessary); Step S34, freeze-thaw cycle 6 times (approximately 4.5 days): each time: freeze at -20°C for 12 h → thaw at 4°C for 6 h.

[0082] Step S35, Core Dissolution (Critical Step): After demolding, immerse the sieve bubble component in a 37°C warm water bath. Warm water enters the sieve bubble through the φ2mm drainage hole pre-installed in the base (if the base has already been assembled). Alternatively, immerse the sieve bubble directly in warm water; the agar balls will dissolve starting from the thinnest part of the wall. Check every 30 minutes by gently shaking the component to feel if the internal agar balls have softened.

[0083] Note: After 2 hours, pour out the dissolved agar solution; 6 interconnected air cells will be visible. Rinse the interior three times with 37°C water to remove residual agar. Inspection: Air cell wall thickness 1~1.5mm, no through holes (paper template sidewalls intact). Defective products: If the air cell walls are too thin (<0.8 mm) or the agar is not completely dissolved, the product is scrapped.

[0084] Step S36: Seal the drain hole: Seal the drain hole of the base with a silicone plug (φ2mm), or pour in a small amount of 8% PVA glue and lightly freeze at -20°C for 30 minutes to seal.

[0085] Step S4: Prepare paper template components: The biomimetic solution consists of 10% PVA and 1% mica powder by mass, with 4 freeze-thaw cycles. The appearance is a 40mm×25mm×1mm thin sheet with a pearlescent luster. The production time is approximately 2 days. The judgment criterion is that it exhibits a pearlescent shimmer under indoor lighting, similar to mother-of-pearl.

[0086] Step S4 specifically includes: Step S41, Weighing (synchronized with the preparation steps of other components): PVA: 5g, mica powder: 1g (pearl grade, particle size 10~60μm), glycerol: 2g, deionized water: 45mL.

[0087] Step S42, Add mica powder (critical step): Add the mica powder to the solution in three batches, 5 minutes apart, while magnetically stirring at 300 rpm. The mica powder should be uniformly suspended without any agglomerated particles. Observation: The solution is milky white, and a pearly shimmer can be seen when the beaker is tilted.

[0088] Step S43, Degassing and Casting: Vacuum degassing for 30 minutes. Mica powder is heavy and may partially settle; gently shake to resuspend it after degassing. The mold is a 40mm × 25mm × 1mm thin frame (two glass plates sandwiching a 1mm silicone gasket). Pretreatment: Spray the glass plates with Vaseline and wipe them unidirectionally with a lint-free cloth (to orient the mica powder and enhance gloss). Pour in the solution and vibrate to remove air for 2 minutes. Horizontally place to prevent mica powder settling and uneven thickness.

[0089] Step S44: 4 freeze-thaw cycles (approximately 3 days).

[0090] Step S45, Demolding and Gloss Inspection: Gently peel off the glass plate; the sheet should peel off completely. Gloss Test: Under indoor lighting, the surface should have a noticeable pearlescent shimmer (similar to mother-of-pearl), creating a strong visual contrast with the surrounding matte film layer. Defective Products: Products with dull gloss (uneven distribution of mica powder) or surface bubbles are rejected.

[0091] Step S5: Preparation of the middle nasal turbinate component: The biomimetic solution is 8% PVA by mass, with 3 freeze-thaw cycles. The component is 50mm × 12mm × 3mm in size, spindle-shaped, and pink. The production time is approximately 1.25 days.

[0092] Step S5 specifically includes: Step S51, Weighing (in sync with the preparation steps of other components): PVA: 4g, Glycerin: 1.5g, Deionized water: 46mL, Pigment: 0.02g each of red and yellow.

[0093] Step S52, Standard Process (Swelling – Dissolving – Degassing – Color Adjustment): Color: Pink, similar to healthy mucous membrane. Mold: Shuttle-shaped silicone mold, 50mm × 12mm × 3mm, with R6 semicircles at both ends. Standard casting, vibration venting.

[0094] Step S53: Repeat freeze-thaw cycles 3 times (approximately 2.25 days).

[0095] Step S54, Demolding and Inspection: Softness Test: Lightly press with a finger; the indentation depth is 3-5 mm, and it rebounds within 2 seconds. Sewing Test: 6-0 sutures pass through without slipping or tearing.

[0096] Step S6: Preparation of the maxillary sinus ostium ring component: A batch of 8% PVA solution can be shared with the middle turbinate; 10 mL can be taken from it. Mold: Elliptical annular groove mold (outer ellipse 8mm × 5mm, inner ellipse 4mm × 1mm, depth 2mm). Slowly inject using a dropper, avoiding air bubbles. Perform 3 freeze-thaw cycles (synchronized with the middle turbinate). Demolding: Gently push the bottom of the annular groove; the ring component will come out. Inspection: The ring is intact without breakage, and the wall thickness is uniform at 2mm.

[0097] Step S7: Preparation of the full-cavity mucosal covering layer (final component): Using 8% PVA by mass, with 3 freeze-thaw cycles, a 0.5~1mm thick film is applied to cover the entire cavity. The process takes approximately 1.25 days. The criteria for evaluation are uniform coverage of all component surfaces and the absence of air bubbles or defects.

[0098] Step S7 specifically includes: Step S71, Solution preparation: PVA: 15 g, glycerin: 5 g, deionized water: 170 mL, pigments: red and yellow 0.1 g. Swell for 30 min → dissolve for 2 h → degas for 30 min.

[0099] Step S72, Base Pre-assembly: Fix the completed skull base, uncinate process, ethmoid bulla, paper template, middle turbinate, and maxillary sinus ostium ring to the corresponding slots on the base. Check the position of each component: uncinate process center (15, -12, 5), ethmoid bulla center (-2, -10, 9), paper template Y=19–20, middle turbinate center (20, 0, 5), maxillary sinus ostium center (25, -15, 5). Apply a small amount of uncrosslinked 8% PVA glue in dots to fix it in place and prevent displacement during casting.

[0100] Step S73, Mucosal Layer Casting (Critical Step): Place the pre-assembled base into the outer mold (including the silicone top cover, inner cavity 80×40×50 mm). A gap of 0.5~1mm is formed between the outer mold and the base (i.e., the mucosal layer space). Slowly inject 8% PVA solution through the inlet hole, with the liquid level gradually rising from the bottom. Injection rate: approximately 5 mL / min, avoiding impact on the components to prevent air bubbles. After filling, vibrate to remove air for 5 minutes. Smooth the liquid surface until it is flush with the upper edge of the outer mold. Note: Due to the thickness of the outer mold, the freezing time is extended to 14 hours to ensure complete internal freezing.

[0101] Step S74: Repeat freeze-thaw cycles 3 times.

[0102] Step S75, Demolding: Remove the outer mold cover. Check the film layer: It should evenly cover all component surfaces, without bubbles or defects. Thickness sampling: Measure 5 points with vernier calipers; the thickness should be 0.5~1mm, with a variation of <0.3mm.

[0103] Step S8, Surface slime coating and final equilibration.

[0104] Step S8 specifically includes: Step S81, Surface Coating: Prepare a 0.5% poloxamer 407 solution: 0.5g poloxamer + 100mL deionized water, stir to dissolve at room temperature. Pour into a spray bottle and spray evenly 2-3 times from a distance of 20cm from the model surface. The coating should be thin and uniform, without forming droplets or drips. Purpose: To simulate the slippery feel of the nasal mucus layer and reduce the coefficient of friction of the instruments.

[0105] Step S82, Moisturizing and Balancing: Place the complete model in a sealed moisturizing box. Line the bottom of the box with damp gauze, and lightly spray the model surface with 1% glycerol-PBS. Equilibrate at 4°C for 24 hours. This allows the mucosal layer to swell and stabilize, achieving the designed mechanical properties.

[0106] Step S83, final acceptance, as shown in Table 1, the acceptance items are the predetermined inspection items.

[0107] Table 1

[0108] In summary, this invention discloses a modular biomimetic training model and its preparation method. The preparation method of the gradient cross-linked modular biomimetic training model includes: determining multiple human tissue modules corresponding to the modular biomimetic training model to be simulated; preparing biomimetic solutions corresponding to each human tissue module using a predetermined hydrophilic polymer material; providing molds corresponding to each human tissue module; injecting each biomimetic solution into the corresponding mold; performing freeze-thaw cycles on each mold with injected biomimetic solution to obtain multiple biomimetic tissue modules with different degrees of cross-linking; installing the multiple biomimetic tissue modules onto corresponding mounting positions on a predetermined substrate to obtain a pre-assembled body; and casting a mucosal layer onto the pre-assembled body to obtain the modular biomimetic training model. This application improves the simulation accuracy of the biomimetic training model by dividing the biomimetic training model into multiple human tissue modules and preparing multiple biomimetic tissue modules with different degrees of cross-linking, thereby obtaining a modular biomimetic training model with near-realistic simulation.

[0109] It should be understood that the application of the present invention is not limited to the examples above. Those skilled in the art can make improvements or modifications based on the above description, and all such improvements and modifications should fall within the protection scope of the appended claims.

Claims

1. A method for preparing a gradient cross-linked modular biomimetic training model, characterized in that, The method includes: Multiple human tissue modules corresponding to the modular biomimetic training model to be simulated were identified, and biomimetic solutions corresponding to each human tissue module were prepared using predetermined hydrophilic polymer materials. Provide molds corresponding to each human tissue module, and inject each biomimetic solution into the corresponding mold respectively; By performing freeze-thaw cycles on each mold that has been injected with biomimetic solution, multiple biomimetic tissue modules with different degrees of cross-linking were obtained. Multiple biomimetic tissue modules are respectively installed in the corresponding mounting positions of a predetermined substrate to obtain a pre-assembled body; A mucosa layer is poured onto the pre-assembled body to obtain a modular biomimetic training model.

2. The method for preparing the gradient cross-linked modular biomimetic training model according to claim 1, characterized in that, Multiple human tissue modules corresponding to the modular biomimetic training model to be simulated were identified, and biomimetic solutions corresponding to each human tissue module were prepared using predetermined hydrophilic polymer materials, including: The modular biomimetic training model to be simulated is identified by determining multiple human tissue modules, the mechanical parameters of different human tissue modules are determined, and the cross-linking degree gradient is determined based on the mechanical parameters. Based on the crosslinking degree gradient, the required ratio of hydrophilic polymer materials and the number of freeze-thaw cycles for the biomimetic solution corresponding to each human tissue module are set. Based on the predetermined ratio of hydrophilic polymer materials, biomimetic solutions corresponding to each human tissue module were prepared.

3. The method for preparing the gradient cross-linked modular biomimetic training model according to claim 2, characterized in that, Freeze-thaw cycles were performed on each mold that had been injected with the biomimetic solution to obtain multiple biomimetic tissue modules with different degrees of cross-linking, including: Based on the number of freeze-thaw cycles corresponding to each human tissue module, freeze-thaw cycles were performed on each mold that had been injected with biomimetic solution to obtain multiple biomimetic tissue modules with different degrees of cross-linking.

4. The method for preparing the gradient cross-linked modular biomimetic training model according to claim 1, characterized in that, A mucosal layer is cast onto the pre-assembled body to obtain a modular biomimetic training model, comprising: An outer mold is provided, the pre-assembled body is placed in the outer mold, and there is a mucous membrane layer space between the pre-assembled body and the outer mold; A hydrophilic polymer solution of predetermined concentration is injected through the inlet hole of the outer mold. After the outer mold filled with hydrophilic polymer solution is subjected to freeze-thaw cycles, it is demolded to obtain a modular biomimetic training model with a mucous membrane layer.

5. The method for preparing the gradient cross-linked modular biomimetic training model according to claim 1, characterized in that, The modular bionic training model is a functional sinus surgery training model. After casting the mucosal layer onto the pre-assembled body to obtain a modular biomimetic training model, the process further includes: A predetermined coating solution is prepared and uniformly sprayed onto the surface of the modular biomimetic training model to simulate the nasal mucus layer. The modular bionic training model was placed in a sealed, moisturizing box, and glycerol phosphate buffer was sprayed onto the surface of the functional sinus surgery training model. The model was then equilibrated at a predetermined temperature for a predetermined duration to allow the mucosal layer to swell and stabilize.

6. The method for preparing the gradient cross-linked modular biomimetic training model according to claim 1, characterized in that, After casting the mucosal layer onto the pre-assembled body to obtain a modular biomimetic training model, the process further includes: Obtain the predetermined test items corresponding to the modular bionic training model, test the modular bionic training model based on each predetermined test item, and obtain the results of each test item. If the results of each test item meet the predetermined qualification standard, the modular bionic training model is successfully prepared.

7. The method for preparing the gradient cross-linked modular biomimetic training model according to claim 1, characterized in that, The predetermined hydrophilic polymer material includes at least one of polyvinyl alcohol, gelatin, and sodium alginate.

8. A modular biomimetic training model with gradient cross-linking, characterized in that, include: The matrix and multiple biomimetic tissue modules; The multiple biomimetic tissue modules are formed and installed at the corresponding mounting positions on the substrate, forming a pre-assembled body according to the position of the human tissue to be simulated; The biomimetic tissue modules in the pre-assembled body are covered with a mucosal layer; each biomimetic tissue module has a different degree of cross-linking, and at least one of the multiple biomimetic tissue modules is installed in the substrate in an independently replaceable manner.

9. The modular biomimetic training model with gradient cross-linking according to claim 8, characterized in that, The modular bionic training model is a functional sinus surgery training model; the multiple bionic tissue modules include components of the skull base and anterior wall of the sphenoid sinus, uncinate process components, ethmoid bulla components, paper template components, middle turbinate components, and maxillary sinus ostium components.

10. The modular biomimetic training model with gradient cross-linking according to claim 8, characterized in that, The multiple biomimetic tissue modules are divided into one-time replacement modules, reusable modules, and permanent modules according to the wear frequency during the training process; the one-time replacement modules, the reusable modules, and the permanent modules are each independently formed and installed in the corresponding mounting positions of the substrate.

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