Personalized ear mold integrated manufacturing method based on multi-material digital light processing

Abstract

The embodiment of the invention discloses a personalized ear mold integrated manufacturing method based on multi-material digital light processing, and relates to the technical field of additive manufacturing. The method comprises the following steps: acquiring a personalized ear mold three-dimensional numerical model of a specific patient; adding a static load based on the dead weight of the hearing aid and a dynamic load based on the periodic force of the chewing motion to the numerical model, and performing dynamic stress analysis on the numerical model based on the added loads; based on a stress analysis result, dividing material areas with different hardness in the numerical model, including a rigid supporting area, a flexible sealing area and a transition area; according to the stress gradient line, the volume fraction of the rigid material and the volume fraction of the flexible material used for DLP three-dimensional printing at all positions in the transition area are determined; and according to the volume fraction and the printing energy density of the rigid supporting area and the printing energy density of the flexible sealing area, the printing energy density of all the positions in the transition area is determined. According to the embodiment, the manufacturing quality and efficiency of the ear mold can be improved.

Description

Technical Field

[0001] The embodiments of the present invention relate to the technical field of additive manufacturing, and particularly to a personalized ear mold integrated manufacturing method based on multi-material digital light processing. Background Art

[0002] As the core carrier of hearing aids, hearing protection devices and ear devices, the manufacturing technology of ear molds has long faced the following difficulties: 1) Defects in manual molding: The existing molding process relies on manual molding (injecting silicone impression material into the ear canal). It is easy for the impression to deform or air bubbles to remain due to the complex shape of the patient's ear canal (such as a curvature > 90°). According to statistics, clinical data shows that about 15% - 20% of ear molds need to be reworked; other methods such as gypsum perfusion have a molding cycle of up to 3 - 7 days, which cannot meet the immediate needs of patients with acute hearing loss.

[0003] 2) Precision and adaptability problems: The surface roughness of manually made ear molds (> 50μm, micrometer) is likely to cause ear canal pressure sores or poor sealing (leakage rate > 10dB, decibel), affecting the acoustic performance of hearing aids; a single material (such as medical silicone) cannot balance the mechanical requirements of different regions of the ear mold (such as the concha cavity requires rigid support, and the ear canal section requires flexible sealing), resulting in poor long-term wearing comfort.

[0004] In recent years, although DLP (Digital Light Processing) technology has been introduced into ear mold manufacturing, there are still significant technical bottlenecks: 1) Limitations of single-material printing: Existing DLP ear molds generally use a single photosensitive resin (such as acrylonitrile-butadiene-styrene copolymer resin), and its elastic modulus is fixed (usually 2 - 3GPa, gigapascal), which cannot meet the requirement of gradual change of material rigidity and flexibility for functional zoning of ear molds (such as the ear canal sealing area requires an elastic modulus of 0.5 - 2MPa (megapascal)); 2) Insufficient precision in dividing rigid and flexible regions of multi-materials: Mostly based on human experience, different material regions are uniformly divided (such as roughly divided into the concha cavity region, ear canal region, etc.), it is difficult to perform a comfortable zoning according to the individual conditions of patients, and it is easy for bending and cracking to occur between regions; 3) Technical obstacles in multi-material printing: Insufficient precision in material switching. Traditional multi-material DLP uses a mechanical nozzle for switching, and the switching interval error > 100μm, resulting in misalignment of materials between layers and affecting the sealing of ear molds; low interfacial bonding strength: The bonding strength between heterogeneous material layers is insufficient (< 5MPa), and delamination and cracking are likely to occur at the bending parts of ear molds; 4) Low post-processing efficiency: The support structure needs to be manually removed, which is likely to damage the fine structures of the ear mold (such as ventilation holes and acoustic channels); the traditional post-processing process of isopropyl alcohol cleaning + ultraviolet secondary curing takes more than 2 hours, and the residual uncured monomers (residual rate > 0.5%) may cause biosafety problems.

[0005] Based on the above difficulties or bottlenecks, the following pain points exist in the entire ear mold manufacturing field: 1) Unable to conform to the trend of personalized medicine: In the trend of increasing demand for customized ear molds, the existing technologies are difficult to achieve the integrated customization of "structure - material - function". 2) Upgrade of patient experience: Clinical research shows that 62% of users reduce the wearing time due to discomfort of the ear mold (discomfort in hardness and poor breathability). 3) Pressure on production cost: The rework rate of traditional ear molds is as high as 20%, which pushes up the unit cost and restricts large-scale popularization. Summary of the Invention

[0006] The embodiments of the present invention provide a method for integrated manufacturing of personalized ear molds based on multi-material digital light processing to solve at least one of the above problems.

[0007] In a first aspect, the embodiments of the present invention provide a method for integrated manufacturing of personalized ear molds based on multi-material digital light processing, including: Obtaining a three-dimensional numerical model of a personalized ear mold for a specific patient; Adding a static load based on the self-weight of the hearing aid and a dynamic load based on the periodic force of chewing movement to the numerical model, and performing dynamic stress analysis on the numerical model based on the added loads; Based on the stress analysis results, dividing different hardness material regions in the numerical model, including a rigid support region, a flexible sealing region, and a transition region; Determining the volume fractions of the rigid material and the flexible material for DLP three-dimensional printing at each position in the transition region according to the stress gradient line; Determining the printing energy density at each position in the transition region according to the volume fractions and the printing energy densities of the rigid support region and the flexible sealing region.

[0008] In a second aspect, the embodiments of the present invention provide an electronic device, which includes: One or more processors; A memory for storing one or more programs, When the one or more programs are executed by the one or more processors, the one or more processors implement the method for integrated manufacturing of personalized ear molds based on multi-material digital light processing according to any embodiment.

[0009] In a third aspect, an embodiment of the present invention further provides a computer-readable storage medium, on which a computer program is stored. When the program is executed by a processor, it implements the personalized ear mold integrated manufacturing method based on multi-material digital light processing described in any of the embodiments.

[0010] In summary, the embodiment of the present invention provides a personalized ear mold integrated manufacturing method based on multi-material digital light processing. First, dynamic stress analysis is performed on the ear mold numerical model according to the actual wearing situation of the hearing aid, and different material regions (including a rigid support region, a flexible sealing region, and a material transition region) are automatically divided according to the stress analysis results, improving the matching accuracy between the region division and the actual force-bearing situation of the hearing aid; then, the material ratio of the material transition region is optimized using stress gradient lines to better fit the irregular shape of the hearing aid and achieve a refined transition of materials and hardness; finally, based on the printing material distribution, through the multi-material DLP printing method and the dynamic mask technology, the light curing wavelength of different regions is controlled to achieve sub-millimeter precision material forming, and truly achieve seamless material gradual change within the same printing layer and material gradual change between printing layers. The method of this embodiment is applicable to customized hearing aids, including behind-the-ear ear molds and customized shells, etc.; it can shorten the ear mold manufacturing cycle to within 4 hours, increase the tensile strength by 30% - 50%, the adjustable range of the elastic modulus of the sealing region reaches 0.5 - 5 MPa, and the surface roughness Ra < 10 μm, greatly improving the cycle and quality of personalized ear mold customization and enhancing the patient experience. Description of the Drawings

[0011] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following will briefly introduce the drawings required for use in the description of the specific embodiments or the prior art. Obviously, the drawings in the following description are some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0012] Figure 1 is a flowchart of a personalized ear mold integrated manufacturing method based on multi-material digital light processing provided by an embodiment of the present invention; Figure 2 is a schematic diagram of an STL model of a simplified ear mold provided by an embodiment of the present invention; Figure 3 is related to Figure 2 corresponding numerical modeling calculation grid division schematic diagram; Figure 4 is related to Figure 3 corresponding region division schematic diagram; Figure 5 is another region division schematic diagram of an ear mold provided by an embodiment of the present invention; Figure 6 It is a schematic diagram of the microstructure of the in-layer material transition corresponding to Figure 4 ; Figure 7 It is a schematic diagram of the microstructure of the inter-layer material transition corresponding to Figure 5 ; Figure 8 It is a schematic diagram of the structure of an electronic device provided by an embodiment of the present invention. Detailed implementation manners

[0013] To make the objectives, technical solutions, and advantages of the present invention clearer, the technical solutions of the present invention will be clearly and completely described below. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the scope of protection of the present invention.

[0014] In the description of the present invention, it should be noted that the orientation or positional relationship indicated by the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation to the present invention. In addition, the terms "first", "second", and "third" are only used for descriptive purposes and cannot be construed as indicating or implying relative importance.

[0015] In the description of the present invention, it should also be noted that unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific situations.

[0016] Figure 1 It is a flowchart of a personalized ear mold integrated manufacturing method based on multi-material digital light processing provided by an embodiment of the present invention. This method is applicable to the situation of manufacturing hearing aid ear molds using DLP 3D (three-dimensional) printing technology and is executed by an electronic device. As Figure 1 shown, this method specifically includes: S110. Obtain a three-dimensional numerical model of a personalized ear mold for a specific patient.

[0017] Generally, the ear mold shapes of different patients are also different. In this embodiment, for different patients, the numerical models of the ear molds of the patients themselves are obtained respectively, providing a basis for the personalized customization of the ear molds.

[0018] In a specific embodiment, a three-dimensional geometric model of the ear mold can be established first. Optionally, for the existing ear sample shape model of the patient, point cloud data is collected through a scanning sensor such as a structured light camera, and the point cloud is generated by aggregation. The STL (StereoLithography) file is generated by fitting the point cloud.

[0019] Then, the STL file is repaired. Optionally, the Marching Cubes algorithm is used to fill the holes in the scanned data; and then the surface noise is eliminated through Laplacian smoothing (for example, iterating 3 times with a smoothing factor of 0.6) (for example, making the surface roughness Ra < 5μm).

[0020] Next, the smoothed geometric model is preprocessed. For the imported three-dimensional scanned model of the patient's ear (in STL format with an accuracy lower than 0.05 mm, millimeter), local defect points are removed, and overall fitting is performed to adapt to subsequent numerical modeling.

[0021] Finally, the three-dimensional model is discretized into a finite element mesh (tetrahedral elements with a side length less than 0.5 mm); due to the different details of the ear molds of different patients, fine meshes can be added locally to improve the expression of the geometric shape. Figure 2 and Figure 3 Taking a simplified customized shell as an example, the differences between the STL model and the meshed model are shown respectively.

[0022] S120. Add a static load based on the self-weight of the hearing aid and a dynamic load based on the periodic force of chewing motion to the numerical model, and perform dynamic stress analysis on the numerical model based on the added loads.

[0023] In this step, an adapted dynamic stress model is constructed according to the force characteristics of the hearing aid during actual wearing to simulate the real force state of the hearing aid. In a specific embodiment, the construction process may include the following steps: Step 1. Set the biomechanical parameters acting on the ear mold, including the elastic modulus of the ear canal skin and the maximum biting force of chewing motion, etc. Among them, the ear canal skin contacts the outer surface of the ear mold, which will affect the force and deformation of the ear mold; and the chewing motion, as an external acting force, will also affect the force state of the ear mold. Therefore, these biomechanical parameters are specifically set in this embodiment to provide a basis for subsequent mechanical analysis. Exemplarily, the elastic modulus of the ear canal skin can be taken as 0.1 - 0.5 MPa, and the maximum biting force of chewing motion can be taken as 50 to 150 N (Newton), and in actual applications, it can be flexibly valued according to the patient's situation.

[0024] Step 2: Set the material model of the ear mold as a linear elastic model, following the generalized Hooke's law. This step sets the material properties of the ear mold, and the mechanical analysis of the ear mold conforms to the generalized Hooke's law: , where σ ij represents the stress tensor, C ijkl represents the material stiffness tensor, represents the strain tensor.

[0025] Step 3: According to the actual wearing situation, set the interface fixed constraint at the contact part between the numerical model and the hearing aid. In this step, the initial condition of the model is set as a free body, and then the boundary condition is set. Optionally, according to the actual wearing situation, set the interface fixed constraint at the contact part between the ear mold and the hearing aid (such as the hearing aid circuit board, etc.), and constrain the displacement degrees of freedom of the connection between the ear mold and the hearing aid buckle along the X / Y / Z directions.

[0026] Step 4: Uniformly apply the self-weight of the hearing aid as a static load at the contact part between the numerical model and the concha; periodically apply the maximum biting force during chewing movement as a dynamic load on the outer surface of the numerical model. In this step, loads are added to the contact part between the ear mold and the ear canal. Among them, the static load includes the self-weight of the hearing aid, which is uniformly distributed on the contact surface of the concha (i.e., the outer shell of the ear mold); the dynamic load includes the periodic force during chewing movement, which is applied to the area of the outer surface of the ear mold where the biting force acts. Exemplarily, the self-weight of the hearing aid can be taken as 10 g (grams), that is, a self-gravity of 0.098 N; the periodic force during chewing movement can be taken as an amplitude of ±20 N and a frequency of 1 Hz (hertz). Similarly, its specific value can be adjusted according to the actual situation of the hearing aid and the patient.

[0027] Step 5: Based on the elastic modulus, interface fixed constraint, and load, perform dynamic stress analysis of the numerical model under the generalized Hooke's law. After the settings in Steps 1 to 4, run the dynamic stress analysis function, and the dynamic stress change of the numerical model under the generalized Hooke's law can be automatically obtained.

[0028] S130: Based on the stress analysis results, divide different material hardness regions in the numerical model, including a rigid support region, a flexible seal region, and a transition region.

[0029] In this step, according to the stress solution results, the ear mold numerical model of this patient is automatically divided into different regions, and each region will correspond to different material hardnesses. Specifically, these regions include a rigid support region (abbreviated as the rigid region), a flexible seal region (abbreviated as the flexible region), and a transition region between the rigid support region and the flexible seal region. Figure 4 and Figure 5The regional division results of two customized housings are respectively shown. Among them, Figure 5 in addition to the above-mentioned several regions, it also includes a breathable region. In this embodiment, the division method of the breathable region is not limited, Figure 5 and it is only used as an example of the division of the above-mentioned rigid region and flexible region.

[0030] In a specific embodiment, the continuous region where the von Mises stress σ vonMises ≥ 5 MPa or the contact pressure p ≥ 0.3 MPa can be divided into a rigid support region using a rigid material; the continuous region where 0.1 MPa ≤ p < 0.3 MPa and the contact area ≥ 50% can be divided into a flexible sealing region using a flexible material. Among them, the above parameters are dynamically changing under dynamic loads. For example, the ear canal will undergo certain deformation during chewing, and the contact area with the outer surface of the hearing aid will change dynamically. Therefore, the parameter values in the above judgment conditions can all be taken as the average values in the dynamic stress analysis.

[0031] S140. Determine the volume fractions of the rigid material and the flexible material for DLP three-dimensional printing at each position in the transition region according to the stress gradient line.

[0032] In this embodiment, in DLP 3D printing, a rigid material with a higher hardness is configured for the rigid support region, a flexible material with a lower hardness is configured for the flexible sealing region, and in the transition region, the volume fractions of the rigid material and the flexible material used at each position are adjusted according to the stress gradient line to obtain a material with a gradually changing hardness. Optionally, the rigid material can be selected as fiberglass-reinforced resin, and the flexible material can be selected as silicone-modified polyurethane acrylate.

[0033] In a specific embodiment, the stress gradient line in the transition region can be determined by the following method: Step 1. Starting from any position in the transition region, extend the stress gradient line along the gradient direction of stress increase and / or stress decrease respectively until the stress gradient line intersects with a rigid support region and / or a flexible sealing region respectively.

[0034] Specifically, in the region division obtained according to the stress analysis results, there can be multiple rigid support regions and multiple flexible sealing regions. Optionally, multiple stress gradient lines can be respectively extended starting from each grid adjacent to any flexible sealing region within the transition region. Taking one of the adjacent grids as an example, starting from this grid, the next grid is determined along the gradient direction of stress increase; then, taking the next grid as the starting point, the next-next grid is determined along the gradient direction of stress increase; and so on, gradually extending until the final grid is adjacent to a rigid support region (i.e., reaching the rigid support region). At this time, the grids determined step by step are connected in sequence according to the order of monotonically increasing stress, and a stress gradient line can be obtained. The above operations are performed for each transition region grid adjacent to the flexible sealing region, and multiple stress gradient lines can be obtained.

[0035] Similarly, multiple stress gradient lines can also be respectively extended starting from each grid adjacent to any rigid support region within the transition region. The difference is that at this time, each step of extension determines the next grid along the gradient direction of stress decrease.

[0036] Step 2: Determine the volume fractions of the rigid material and the flexible material for DLP three-dimensional printing at the arbitrary position according to the length of the stress gradient line after intersection and the position of the arbitrary position in the stress gradient line after intersection.

[0037] In this embodiment, in the transition region, along the direction from the rigid support region to the flexible sealing region, the volume fraction of the rigid material V r gradually decreases from 100% to 0%, and the volume fraction of the flexible material V f gradually increases from 0% to 100%. Optionally, the volume fractions of the rigid material and the flexible material at each intermediate position can be determined according to the following formula:

[0038]

[0039] where, L is the length of the stress gradient line where the arbitrary position is located; x represents the distance from the arbitrary position to the rigid support region at one end of the stress gradient line along the direction of the stress gradient line. This formula takes the rigid material as the reference point and gradually performs smooth transition of the material ratio and hardness using trigonometric functions, fully avoiding material mutation around the rigid material; compared with the linear change formula, the material transition of this formula is smoother, further improving the stability of the joint surface of different materials. In the actual printing process, the selection of a single-layer material can be jointly determined based on the material mixing accuracy and the calculated volume fraction.

[0040] Specifically, due to the irregular shape of the ear mold, the following two special cases may be encountered during the determination of the volume fraction: Case 1: A certain grid sequence belongs to multiple stress gradient lines. For example, in the part of the ear mold where the width changes from wide to narrow, if the grid in the wider part is used as the starting point to determine the stress gradient line, there may be a situation where multiple stress gradient lines converge into one at the narrowing part of the structure. In this case, when calculating the volume fraction, the shortest one among all the gradient lines passing through the converging part should be processed first, and the length of this gradient line should be used as the length in the above formula L , and the volume fraction of each grid on this gradient line should be determined preferentially. This is because the shortest stress gradient line is most likely to have a material mutation. Prioritizing the uniform change of materials in this direction is more conducive to the smooth transition of the entire ear mold. After the volume fraction of the converging part (also called the converging section) is determined, for other stress gradient lines drawn from this converging section along the gradient direction of stress decrease, the drawn part can be called the remaining section, and the material volume fraction at the intersection of this converging section and the remaining section V r0 is used as the reference point, and the following formula is used to determine the material volume fraction of each grid in the remaining section:

[0041]

[0042] At this time L is the length of the remaining section, x represents the distance from any position in the remaining section to the intersection point along the direction of the other stress gradient line.

[0043] Case 2: A certain grid sequence does not belong to any stress gradient line. For example, in the part of the ear mold where the width changes from narrow to wide, if the grid in the narrower part is used as the starting point to determine the stress gradient line, there may be a situation where some grids do not belong to any stress gradient line at the widening part of the structure. At this time, any point in these grids can be used as the starting point, and stress gradient lines can be re-extended along the gradient direction of stress increase and / or decrease, and these gradient lines can be connected to the grids with the closest surrounding stress values and merged into the existing stress gradient lines. At this time, the distribution of the stress gradient lines and the grids changes to Case 1, and it can be processed in the same way as Case 1.

[0044] S150. Determine the printing energy density at each position in the transition region according to the volume fraction and the printing energy density of the rigid support region and the flexible sealing region.

[0045] Based on the above volume fractions, the printing material ratio of multi-material DLP can be carried out in this embodiment. Match the photosensitive resin combinations in the material library according to the regional characteristics (such as high-rigidity resin, flexible thermoplastic polyurethane rubber resin, biocompatible resin, etc.); and at the junction of the rigid area and the flexible area, avoid stress concentration through a gradual change in the material ratio.

[0046] In addition, the multi-material DLP printing process planning can also be carried out. Using a digital micromirror device and an ultraviolet LED array (dual wavelength of 365nm / 405nm), control the curing depth of different regions (50 - 200μm) by real-time refreshing of the mask pattern (refresh rate ≥ 120Hz). Through the multi-material DLP printing control method, selectively cure different regions: for example, use 405nm (nanometer) high-energy curing in the rigid region (energy density 20mJ / cm², millijoules per square centimeter); use 365nm low-energy curing in the flexible region (energy density 8mJ / cm²) to avoid embrittlement caused by over-crosslinking; at the material junction (such as the rigid → flexible transition region), achieve a gradient distribution of exposure energy through a grayscale mask (grayscale value 50 - 200) to form an interpenetrating network structure.

[0047] Generally speaking, the overall printing control strategy in the above examples is: Rigid region: 405nm wavelength, energy density E r =20mJ / cm 2 ; Flexible region: 365nm wavelength, energy density E f =8mJ / cm 2 ; Exposure energy in the transition region E transition Weighted by material ratio: .

[0048] After calculation, according to the printing energy density at each grid position of the three-dimensional numerical model, layer by layer construct the grayscale mask of the printing surface; in DLP three-dimensional printing, according to the volume fractions of the two materials at each grid position, control the material ratio at each grid position, and at the same time, according to the grayscale mask of each printing surface, control the curing depth of the digital micromirror device and the ultraviolet LED array to achieve seamless hardness gradient within the same layer printing surface (as shown in Figure 6 ), and hardness gradient between different layer printing surfaces (as shown in Figure 7 ).

[0049] Furthermore, the ear mold support structure uses a water-soluble photosensitive resin, and its printing parameters can be optimized synchronously with the main structure. After multi-material DLP printing, a dissolvable support structure design can be adopted to optimize the support layout to reduce post-processing damage.

[0050] In summary, this embodiment provides a personalized ear mold integrated manufacturing method based on multi-material digital light processing. First, a dynamic stress analysis is performed on the ear mold numerical model according to the actual wearing situation of the hearing aid, and different material regions (including a rigid support region, a flexible sealing region, and a material transition region) are automatically divided according to the stress analysis results, improving the matching accuracy between the region division and the actual force-bearing situation of the hearing aid. Then, the material ratio of the material transition region is optimized using stress gradient lines to better fit the irregular shape of the hearing aid and achieve a refined transition of materials and hardness. Among them, the trigonometric function ratio method with the rigid material region as the reference point achieves a better smooth transition and fully ensures the stability of material connection. Finally, based on the printing material distribution, through the multi-material DLP printing method and the dynamic mask technology, the light curing wavelength of different regions is controlled to achieve sub-millimeter precision material forming, and seamless material gradient within the same printing layer and material gradient between printing layers are truly realized. The method of this embodiment is applicable to customized hearing aids, including behind-the-ear ear molds and customized shells, etc.; it can shorten the ear mold manufacturing cycle to within 4 hours, increase the tensile strength by 30%-50%, the adjustable range of the elastic modulus in the sealing region reaches 0.5-5 MPa, the residual rate of the support structure is less than 0.1%, and the surface roughness Ra < 10 μm, greatly improving the cycle and quality of personalized ear mold customization and enhancing the patient experience.

[0051] Figure 8 FIG. is a schematic structural diagram of an electronic device provided by an embodiment of the present invention, as Figure 8 shown, the device includes a processor 60, a memory 61, an input device 62, and an output device 63; the number of processors 60 in the device can be one or more, Figure 8 taking one processor 60 as an example; the processor 60, the memory 61, the input device 62, and the output device 63 in the device can be connected through a bus or other means, Figure 8 taking the connection through a bus as an example.

[0052] The memory 61, as a computer-readable storage medium, can be used to store software programs, computer-executable programs, and modules, such as the program instructions / modules corresponding to the personalized ear mold integrated manufacturing method based on multi-material digital light processing in the embodiment of the present invention. The processor 60 executes various functional applications and data processing of the device by running the software programs, instructions, and modules stored in the memory 61, that is, implements the above-mentioned personalized ear mold integrated manufacturing method based on multi-material digital light processing.

[0053] The memory 61 may mainly include a program storage area and a data storage area. Among them, the program storage area may store an operating system and application programs required for at least one function; the data storage area may store data created according to the use of the terminal, etc. In addition, the memory 61 may include a high-speed random access memory, and may also include a non-volatile memory, such as at least one magnetic disk storage device, a flash memory device, or other non-volatile solid-state storage devices. In some instances, the memory 61 may further include a memory remotely provided with respect to the processor 60, and these remote memories may be connected to the device through a network. Examples of the above network include but are not limited to the Internet, an intranet, a local area network, a mobile communication network, and combinations thereof.

[0054] The input device 62 may be used to receive input digital or character information, and generate key signal inputs related to user settings and function controls of the device. The output device 63 may include a display device such as a display screen.

[0055] An embodiment of the present invention also provides a computer-readable storage medium, on which a computer program is stored, and when the program is executed by a processor, it implements the personalized ear mold integrated manufacturing method based on multi-material digital light processing in any embodiment.

[0056] The computer storage medium of the embodiment of the present invention may adopt any combination of one or more computer-readable media. The computer-readable medium may be a computer-readable signal medium or a computer-readable storage medium. The computer-readable storage medium may be, for example, but not limited to, an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any combination of the above. More specific examples (non-exhaustive list) of the computer-readable storage medium include: an electrical connection having one or more wires, a portable computer disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber, a portable compact disk read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the above. In this document, the computer-readable storage medium may be any tangible medium that contains or stores a program, and this program may be used by or in combination with an instruction execution system, apparatus, or device.

[0057] The computer-readable signal medium may include a data signal propagated in a baseband or as part of a carrier wave, in which computer-readable program code is carried. Such a propagated data signal may take various forms, including but not limited to electromagnetic signals, optical signals, or any suitable combination of the above. The computer-readable signal medium may also be any computer-readable medium other than the computer-readable storage medium, and this computer-readable medium may send, propagate, or transmit a program for use by or in combination with an instruction execution system, apparatus, or device.

[0058] The program code contained on a computer-readable medium can be transmitted with any suitable medium, including but not limited to wireless, wire, optical fiber cable, RF, etc., or any suitable combination of the above.

[0059] The computer program code for performing the operations of the present invention can be written in one or more programming languages or combinations thereof. The programming languages include object-oriented programming languages such as Java, Smalltalk, C++, and also include conventional procedural programming languages such as C language or similar programming languages. The program code can be executed entirely on the user's computer, partially on the user's computer, executed as an independent software package, partially on the user's computer and partially on a remote computer, or entirely on a remote computer or server. In the case of a remote computer, the remote computer can be connected to the user's computer through any type of network, including a local area network (LAN) or a wide area network (WAN), or can be connected to an external computer (for example, by using an Internet service provider to connect through the Internet).

[0060] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit them. Although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements for some or all of the technical features; and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the technical solutions of the embodiments of the present invention.

Claims

1. A personalized ear mold integrated manufacturing method based on multi-material digital light processing, characterized in that Including: Obtaining a personalized three-dimensional numerical model of an ear mold for a specific patient; Adding a static load based on the self-weight of the hearing aid and a dynamic load based on the periodic force of chewing motion to the numerical model, and performing dynamic stress analysis on the numerical model based on the added loads; Based on the stress analysis results, dividing different hardness material regions in the numerical model, including a rigid support region, a flexible sealing region, and a transition region; Determining the volume fractions of the rigid material and the flexible material for DLP three-dimensional printing at each position in the transition region according to the stress gradient line; Determining the printing energy density at each position in the transition region according to the volume fractions and the printing energy densities of the rigid support region and the flexible sealing region.

2. The method according to claim 1, wherein adding a static load based on the self-weight of the hearing aid and a dynamic load based on the periodic force of chewing motion to the numerical model, and performing dynamic stress analysis under the added loads, includes: Setting the elastic modulus of the ear canal skin and the maximum biting force of chewing motion; Setting the material model of the ear mold as a linear elastic model, following the generalized Hooke's law; Setting interface fixed constraints at the contact part between the numerical model and the hearing aid according to the actual wearing situation; Uniformly applying the self-weight of the hearing aid as a static load at the contact part between the numerical model and the concha; Periodically applying the maximum biting force of chewing motion as a dynamic load on the outer surface of the numerical model; Performing dynamic stress analysis of the numerical model under the generalized Hooke's law based on the elastic modulus, interface fixed constraints, and loads.

3. The method according to claim 1, wherein The dividing different hardness material regions in the numerical model based on the stress analysis results includes: Dividing the continuous region where the von Mises stress in the stress analysis is ≥ the first threshold or the contact pressure is ≥ the second threshold into a rigid support region using a rigid material; Dividing the continuous region where the third threshold ≤ the contact pressure < the second threshold and the contact area with the ear canal ≥ the fourth threshold into a flexible sealing region using a flexible material.

4. The method according to claim 1, characterized in that The determining the volume fractions of the rigid material and the flexible material for DLP three-dimensional printing at each position in the transition region according to the stress gradient line includes: Taking an arbitrary position in the transition region as a starting point, respectively extending the stress gradient line along the stress rising and / or stress falling gradient directions until the stress gradient line intersects with a rigid support region and / or a flexible sealing region respectively; Determining the volume fractions of the rigid material and the flexible material for DLP three-dimensional printing at the arbitrary position according to the length of the stress gradient line after intersection and the position of the arbitrary position in the stress gradient line after intersection.

5. The method according to claim 4, characterized in that, The taking an arbitrary position in the transition region as a starting point, respectively extending the stress gradient line along the stress rising and / or stress falling gradient directions until the stress gradient line intersects with a rigid support region and / or a flexible sealing region respectively includes: Taking an arbitrary grid adjacent to a flexible sealing region in the transition region as a starting point, gradually determining multiple grids along the stress rising gradient direction until the final grid intersects with a rigid support region; Connect the gradually determined grids in sequence according to the order of monotonically increasing stress to obtain a stress gradient line.

6. The method according to claim 1, characterized in that, Determining the volume fractions of the rigid material and the flexible material for DLP three-dimensional printing at each position in the transition region according to the stress gradient line includes: Determine the volume fraction of the rigid material for DLP three-dimensional printing at any position within the transition region according to the following formula V r (x): Wherein, L is the length of the stress gradient line where the arbitrary position is located; x represents the distance from the arbitrary position to the rigid support region at one end of the stress gradient line in the direction along the stress gradient line.

7. The method according to claim 1, wherein After determining the printing energy density at each position in the transition region according to the volume fraction and the printing energy density of the rigid support region and the flexible sealing region, it further includes: Construct a grayscale mask of the printing surface layer by layer according to the printing energy density at each grid position of the three-dimensional numerical model; In DLP three-dimensional printing, control the material ratio at each grid position according to the volume fractions of the two materials at each grid position, and control the wavelength curing depth according to the grayscale mask of each printing surface to achieve a gradual change in hardness within the same-layer printing surface and between different-layer printing surfaces.

8. The method according to claim 1, characterized in that, The rigid material includes glass fiber reinforced resin, and the flexible material includes silicone modified polyurethane acrylate.

9. An electronic device, characterized in that, It includes: One or more processors; A memory for storing one or more programs, When the one or more programs are executed by the one or more processors, the one or more processors implement the personalized ear mold integrated manufacturing method based on multi-material digital light processing according to any one of claims 1-8.

10. A computer-readable storage medium, characterized in that, A computer program is stored thereon, and when the program is executed by a processor, it implements the personalized ear mold integrated manufacturing method based on multi-material digital light processing according to any one of claims 1-8.

Images