Prosthesis socket model optimization design method and device, electronic equipment and product

Abstract

The application discloses a PTB receiving cavity model optimization design method and device, electronic equipment and products, and relates to the technical field of rehabilitation engineering and rehabilitation aids. The application divides the inner surface of a prosthesis receiving cavity model into a pressure sensitive area and a pressure resistant area, simulates the maximum ground reaction force loading of single leg support when a below-knee amputee wears a prosthesis, and then iteratively optimizes the displacement increment of the grid surface in each pressure resistant area through an optimization algorithm with the maximum overall comfort of the prosthesis receiving cavity model as the target, so that the individual differences of the below-knee amputee can be optimized and designed, the stress concentration in the sensitive area and the insufficient support in the resistant area can be avoided, the discomfort, pain and even secondary injury of the below-knee amputee can be avoided, and the use experience of the below-knee amputee is improved.

Description

PTB receiving cavity model optimization design method, device, electronic equipment and products Technical Field

[0001] This invention belongs to the field of rehabilitation engineering and rehabilitation aids technology, specifically relating to a PTB receiver cavity model optimization design method, device, electronic equipment and product. Background Technology

[0002] The PTB (Patellar Tendon Bearing Socket) is a classic type of socket designed for patients with lower leg amputations in prosthetic technology. Its core principle is to achieve physiological weight transfer through the patellar ligament.

[0003] Traditional PTB socket fabrication involves a complex manual process by assistive device manufacturers, including taking the mold, pouring the positive mold, modifying the positive mold, and fabricating and modifying the socket and inner liner. The design and adjustments rely entirely on the technician's experience and judgment, and each procedure takes more than 48 hours, which severely restricts the efficiency of clinical fitting. Furthermore, when using a PTB socket in patients with lower leg amputations, there may be stress concentration between the stump and the inner wall of the socket, resulting in stress concentration in the sensitive area and insufficient support in the tolerance area. This can cause discomfort, pain, or even secondary injury to the prosthesis wearer.

[0004] Therefore, how to provide an effective solution to improve the design efficiency of the PTB receiving cavity and avoid the problem of local stress concentration in the PTB receiving cavity has become an urgent problem to be solved in the existing technology. Summary of the Invention

[0005] The purpose of this invention is to provide a PTB receiving cavity model optimization design method, device, electronic device and product to solve the above-mentioned problems existing in the prior art.

[0006] To achieve the above objectives, the present invention adopts the following technical solution:

[0007] In a first aspect, the present invention provides a method for optimizing the design of a PTB receiving cavity model, comprising:

[0008] Constructing a soft tissue model of the residual limb from a patient with lower leg amputation;

[0009] Based on the residual limb soft tissue model, construct an inner liner model and a prosthesis socket model;

[0010] Construct a connector model, and assemble the residual limb soft tissue model, the inner liner model, the prosthesis receiving cavity model, and the connector model to obtain an assembled model;

[0011] The prosthesis socket model is meshed;

[0012] Material properties are assigned to each model in the assembly model, and a coordinate system is established with the direction of the connector model toward the prosthesis socket model as the Z-axis direction.

[0013] Under the condition of constraining the degree of freedom of the top cutting surface of the residual limb soft tissue model, a load is applied to the bottom of the connector model. The applied load is the maximum ground reaction force simulating the single-leg support when the lower leg amputee patient walks with a prosthesis.

[0014] The inner surface of the prosthesis socket model is divided into multiple pressure-sensitive areas and multiple pressure-tolerant areas;

[0015] Based on applying a load to the bottom of the connector model, a force model for the mesh surface in each pressure-sensitive region and a force model for the mesh surface in each pressure-resistant region are established.

[0016] Based on the force constraints of the grids in each pressure-sensitive region and the grids in each pressure-tolerant region, with the goal of maximizing the overall comfort of the prosthetic socket model, the displacement increments of the grid surfaces in each pressure-sensitive region and the grid surfaces in each pressure-tolerant region are iteratively optimized using a target optimization algorithm. The overall comfort of the prosthetic socket model is determined based on the contact pressure of the grid surfaces in each pressure-sensitive region, the force constraints of the grids in each pressure-sensitive region, the contact pressure of the grid surfaces in each pressure-tolerant region, and the force constraints of the grids in each pressure-tolerant region.

[0017] When the iteration stopping condition is met, the inner wall shape of the prosthetic socket model is adjusted based on the displacement increment of the grid surface in each pressure-sensitive region and the displacement increment of the grid surface in each pressure-tolerant region, to obtain the PTB socket model of the lower leg amputee patient.

[0018] In one possible design, constructing a soft tissue model of the residual limb from a lower leg amputee patient includes:

[0019] Obtain CT scan images of the lower leg stump from patients who have undergone lower leg amputation;

[0020] A three-dimensional model of the lower leg stump was constructed based on the CT scan images;

[0021] The three-dimensional model of the lower leg stump was smoothed to obtain the soft tissue model of the stump of the patient with lower leg amputation.

[0022] In one possible design, an inner liner model and a prosthesis socket model are constructed based on the residual limb soft tissue model, including:

[0023] Based on the external contour of the residual limb soft tissue model, the inner surface shape of the inner liner model is constructed.

[0024] Based on the inner surface shape of the inner liner model, the outer thickness is increased by a first specified thickness to obtain the inner liner model;

[0025] Based on the outer contour of the inner liner model, the inner surface shape of the prosthesis socket model is constructed.

[0026] Based on the inner surface shape of the prosthesis socket model, a second specified thickness is added outward to obtain the prosthesis socket model.

[0027] In one possible design, the prosthetic socket model is meshed, including:

[0028] The prosthesis socket model is meshed in 2D.

[0029] The 2D mesh of the prosthesis socket model is optimized and adjusted;

[0030] The optimized 2D mesh is divided into 3D tetrahedral meshes to obtain the 3D tetrahedral mesh of the prosthesis socket model.

[0031] In a possible design, the material properties assigned to each model include density, elastic modulus, and / or Poisson's ratio.

[0032] In one possible design, the plurality of pressure-sensitive regions include the tibial crest region, the fibular end region, the fibular head region, and / or the tibial end region, and the plurality of pressure-tolerant regions include the patellar tendon region, the anteromedial tibial region, the anterolateral tibial region, and / or the popliteal fossa region.

[0033] In one possible design, the overall comfort of the prosthetic socket model is negatively correlated with the mean square error of the difference between the contact pressure of the grid surface in each region and the corresponding force constraint.

[0034] Secondly, the present invention provides a PTB receiver cavity model optimization design device, comprising:

[0035] The first building unit is used to construct a soft tissue model of the residual limb of a patient with lower leg amputation.

[0036] The second construction unit is used to construct an inner liner model and a prosthesis socket model based on the residual limb soft tissue model.

[0037] The construction and assembly unit is used to construct the connector model and assemble the residual limb soft tissue model, the inner liner model, the prosthesis receiving cavity model and the connector model to obtain the assembly model;

[0038] Mesh generation unit, used to perform mesh generation on the prosthesis socket model;

[0039] The coordinate system establishment unit is used to assign material properties to each model in the assembly model and to establish a coordinate system with the direction of the connector model toward the prosthesis receiving cavity model as the Z-axis direction.

[0040] The load application unit is used to apply a load to the bottom of the connector model under the condition of constraining the degree of freedom of the top cutting surface of the residual limb soft tissue model. The applied load is the maximum ground reaction force simulating the single-leg support when the lower leg amputee patient walks with a prosthesis.

[0041] A region division unit is used to divide the inner surface of the prosthesis socket model into multiple pressure-sensitive regions and multiple pressure-tolerant regions;

[0042] The stress model establishment unit is used to establish stress models of the grid surfaces in each pressure-sensitive region and the grid surfaces in each pressure-resistant region based on the load applied to the bottom of the connector model.

[0043] An iterative optimization unit is used to iteratively optimize the displacement increments of the grid surfaces in each pressure-sensitive region and each pressure-tolerant region based on the force constraints of the grid in each pressure-sensitive region and the force constraints of the grid in each pressure-tolerant region, with the goal of maximizing the overall comfort of the prosthetic socket model. The overall comfort of the prosthetic socket model is determined based on the contact pressure of the grid surfaces in each pressure-sensitive region, the force constraints of the grid in each pressure-sensitive region, the contact pressure of the grid surfaces in each pressure-tolerant region, and the force constraints of the grid in each pressure-tolerant region.

[0044] An adjustment unit is used to adjust the inner wall shape of the prosthetic socket model based on the displacement increment of the grid surface in each pressure-sensitive region and the displacement increment of the grid surface in each pressure-tolerant region when the iteration stopping condition is reached, so as to obtain the PTB socket model of the lower leg amputee patient.

[0045] Thirdly, the present invention provides an electronic device comprising a memory, a processor, and a transceiver connected in sequence and communication, wherein the memory is used to store a computer program, the transceiver is used to send and receive messages, and the processor is used to read the computer program and execute the PTB receiving cavity model optimization design method as described in the first aspect or any possible design of the first aspect.

[0046] Fourthly, the present invention provides a computer-readable storage medium storing instructions that, when executed on a computer, perform the PTB receiving cavity model optimization design method described in the first aspect or any possible design of the first aspect.

[0047] Fifthly, the present invention provides a computer program product containing instructions that, when executed on a computer, cause the computer to perform the PTB receiver cavity model optimization design method as described in the first aspect or any possible design of the first aspect.

[0048] Beneficial effects:

[0049] This invention, in designing the PTB socket model, divides the inner surface of the prosthetic socket model into pressure-sensitive and pressure-tolerant regions. It simulates the maximum ground reaction force applied to a single leg during walking with a prosthesis in a lower leg amputee. Then, aiming for maximum overall comfort of the prosthetic socket model, an optimization algorithm iteratively optimizes the displacement increment of the grid surface in each pressure-tolerant region. This allows for optimized design tailored to the individual differences of lower leg amputees, avoiding stress concentration in sensitive areas and insufficient support in pressure-tolerant areas. This prevents discomfort, pain, or even secondary injury to lower leg amputees, improving their user experience. Furthermore, it enables automatic optimization design of the PTB socket, improving design efficiency and facilitating practical application and widespread adoption. Attached Figure Description

[0050] Figure 1 is a flowchart of the PTB receiving cavity model optimization design method provided in an embodiment of this application;

[0051] Figure 2 is a block diagram of the PTB receiving cavity model optimization design device provided in an embodiment of this application;

[0052] Figure 3 is a block diagram of the electronic device provided in an embodiment of this application. Detailed Implementation

[0053] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the present invention will be briefly introduced below in conjunction with the accompanying drawings and descriptions of the embodiments or the prior art. Obviously, the following description of the structure of the accompanying drawings is only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort. It should be noted that the description of these embodiments is for the purpose of helping to understand the present invention, but does not constitute a limitation of the present invention.

[0054] It should be understood that although the terms first, second, etc., may be used herein to describe various units, these units should not be limited by these terms. These terms are only used to distinguish one unit from another. For example, a first unit may be referred to as a second unit, and similarly, a second unit may be referred to as a first unit, without departing from the scope of the exemplary embodiments of the invention.

[0055] It should be understood that the term "and / or" that may appear in this document is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can mean: A exists alone, B exists alone, and A and B exist simultaneously. The term " / and" that may appear in this document describes another relationship between related objects, indicating that two relationships can exist. For example, A / and B can mean: A exists alone, and A and B exist alone. In addition, the character " / " that may appear in this document generally indicates that the related objects before and after it are in an "or" relationship.

[0056] It should be understood that specific details are provided in the following description to facilitate a complete understanding of the exemplary embodiments. However, those skilled in the art will understand that the exemplary embodiments can be implemented without these specific details. For example, the system may be shown in block diagrams to avoid obscuring the example with unnecessary details. In other instances, well-known processes, structures, and techniques may be shown without unnecessary details to avoid obscuring the exemplary embodiments.

[0057] To avoid the problem of local stress concentration in the PTB socket, this application provides a PTB socket model optimization design method, device, electronic device, and product. This PTB socket model optimization design method, device, electronic device, and product can avoid stress concentration in sensitive areas and insufficient support in tolerance areas, improve the user experience for patients with lower leg amputations, and improve the design efficiency of the PTB socket.

[0058] The PTB receiving cavity model optimization design method provided in the application embodiment can be applied to user terminals or servers. The user terminal can be, but is not limited to, personal computers, smartphones, tablets, laptop computers, personal digital assistants (PDAs), etc.

[0059] It is understood that the execution entity described herein does not constitute a limitation on the embodiments of this application. The PTB receiving cavity model optimization design method provided in the embodiments of this application will be described in detail below.

[0060] As shown in Figure 1, the first aspect of this embodiment provides a PTB receiver cavity model optimization design method, which may include the following steps S101-S110.

[0061] Step S101. Construct a soft tissue model of the residual limb of a patient with lower leg amputation.

[0062] In one or more embodiments, when constructing a soft tissue model of the stump of a patient with lower leg amputation, the patient can first be required to lie down with the stump exposed, and CT scan images of the lower leg stump can be obtained using a CT scanner. Then, a three-dimensional model of the lower leg stump is constructed based on the CT scan images. This three-dimensional model can be constructed using, but is not limited to, MIMICS (Materialise's interactive medical image control system, a medical image control system invented by Materialise) or 3D Slicer (an open-source, free, and scalable medical image processing and visualization application platform). Finally, the three-dimensional model of the lower leg stump is smoothed to obtain the soft tissue model of the lower leg stump.

[0063] Understandably, in some other embodiments, a soft tissue model of the residual limb of a patient with a lower leg amputation can also be obtained by directly scanning with a 3D scanner.

[0064] Step S102. Construct the inner liner model and the prosthesis socket model based on the residual limb soft tissue model.

[0065] Specifically, the inner surface shape of the inner liner model can be constructed first based on the outer contour of the residual limb soft tissue model. Then, based on the inner surface shape of the inner liner model, a first specified thickness (e.g., 5mm) is added outward to obtain the inner liner model. Next, based on the outer contour of the inner liner model, the inner surface shape of the prosthesis socket model is constructed. Finally, based on the inner surface shape of the prosthesis socket model, a second specified thickness (e.g., 4mm) is added outward to obtain the prosthesis socket model.

[0066] Step S103. Construct the connector model, and assemble the residual limb soft tissue model, inner liner model, prosthesis socket model and connector model to obtain the assembled model.

[0067] In one or more embodiments, the connector can be directly constructed using Solidworks (a 3D computer-aided design software developed by Dassault Systèmes of France, widely used in product design, engineering and manufacturing). The connector can be constructed according to the connector size currently used in the market. After the connector model is constructed, the residual limb soft tissue model, the inner liner model, the prosthesis socket model and the connector model are assembled to obtain the assembled model.

[0068] During assembly, the residual limb soft tissue model can be placed inside the inner liner model, the inner liner model can be placed inside the prosthesis socket model, and the end of the prosthesis socket model facing away from the opening can be connected to one end of the connector model to simulate the situation of a lower leg amputee patient wearing a prosthesis normally.

[0069] Step S104. Mesh the prosthesis socket model.

[0070] When meshing, the prosthesis socket model can be meshed in 2D first, then the 2D mesh of the prosthesis socket model can be optimized and adjusted, and finally the optimized 2D mesh can be meshed in 3D tetrahedron to obtain the 3D tetrahedron mesh of the prosthesis socket model. The meshed 3D tetrahedron mesh must meet the requirements and have no negative volume mesh.

[0071] Among them, optimizing and adjusting the 2D mesh of the prosthesis socket model can be done by determining whether the aspect ratio (the ratio between the height and width of the mesh) of the 2D mesh is within a preset range. If it exceeds the range, the size of the 2D mesh is adjusted so that the aspect ratio of the 2D mesh is within the preset range.

[0072] Step S105. Assign material properties to each model in the assembly model, and establish a coordinate system with the direction of the connector model toward the prosthesis cavity model as the Z-axis direction.

[0073] In one or more embodiments, material properties can be assigned to the individual models in the assembly model using ABAQUS (a powerful, general-purpose finite element software for engineering simulation developed by Dassault Systèmes, which focuses on solving engineering simulation needs ranging from simple linear analysis to complex nonlinear problems).

[0074] The material properties assigned to each model include, but are not limited to, density, elastic modulus, and / or Poisson's ratio. For example, for a residual limb soft tissue model, the material properties density, elastic modulus, and Poisson's ratio can be assigned. The density can be set to 1000 kg / m³, the elastic modulus to 0.3 MPa, and the Poisson's ratio to 0.45. For a prosthesis socket model, the material properties density, elastic modulus, and Poisson's ratio can be assigned. The density can be set to 800 kg / m³, the elastic modulus to 19000 MPa, and the Poisson's ratio to 0.1. For an inner liner model, the material properties elastic modulus and Poisson's ratio can be assigned. The elastic modulus can be set to 0.38 MPa, and the Poisson's ratio to 0.39.

[0075] When establishing a coordinate system, a local coordinate system can be established or the global coordinate system can be moved. The coordinate system is established with the direction of the connector model toward the prosthesis socket model as the Z-axis direction.

[0076] Step S106. Under the condition of constraining the degree of freedom of the top cutting surface of the residual limb soft tissue model, apply a load to the bottom of the connector model.

[0077] The applied load is the maximum ground reaction force simulating the single-leg support of a lower leg amputee walking with a prosthesis. The maximum ground reaction force of a single leg supporting a person walking at normal speed can reach 120%-140% of body weight. Therefore, the load applied to the bottom of the connector model can be between 1.2 and 1.4 times the body weight of the lower leg amputee patient. In one or more embodiments, taking 1.2 times the body weight of the lower leg amputee patient as a conservative working condition value for the load applied to the bottom of the connector model avoids overestimation leading to design redundancy while ensuring coverage of the mechanical needs of most patients.

[0078] Step S107. Divide the inner surface of the prosthesis socket model into multiple pressure-sensitive areas and multiple pressure-tolerant areas.

[0079] In one or more embodiments, the inner surface of the prosthetic socket model can be divided into four pressure-sensitive regions and four pressure-tolerant regions. The four pressure-sensitive regions include the tibial crest region (TC), fibular end region (FE), fibular head region (FH), and tibial end region (TE). The four pressure-tolerant regions include the patellar tendon region (PT), anteromedial tibia region (AMT), anterolateral tibia region (ALT), and popliteal depression region (PD).

[0080] Step S108. Based on applying a load to the bottom of the connector model, establish the force model of the mesh surface in each pressure-sensitive region and the force model of the mesh surface in each pressure-resistant region.

[0081] Step S109. Based on the force constraints of the meshes in each pressure-sensitive region and the meshes in each pressure-tolerant region, with the goal of maximizing the overall comfort of the prosthesis socket model, the displacement increment of the mesh surface in each pressure-sensitive region and the displacement increment of the mesh surface in each pressure-tolerant region are iteratively optimized using a target optimization algorithm.

[0082] The force constraint of each pressure-sensitive region grid can refer to the maximum contact pressure per unit area allowed to be applied to each pressure-sensitive region grid, and the force constraint of each pressure-resistant region grid can refer to the maximum contact pressure per unit area allowed to be applied to each pressure-resistant region grid.

[0083] During iterative optimization, the Shape-controller algorithm can be used for shape control calculations. The region basis vector output by the Shape-controller algorithm is... Then the Morphing transformation formula is defined as:

[0084]

[0085] in: : The final shape vector of region k ( ∈{TC,FH,…,PD}); Morphing variables (design variables); : Regional material deformation coefficient.

[0086] Morphing variables can be represented by an experiment matrix MM, which is an n×8 design matrix (where n is the number of trials). Its mathematical expression is as follows:

[0087]

[0088] in, This refers to the first iteration operation of each region; This refers to the nth iteration operation in each region;

[0089] The force model for targets (TC, FH, FE, TE) in the pressure-sensitive zone can be expressed as:

[0090]

[0091]

[0092] in, It is a weighted sum of the squared deviations of the actual pressure in all sensitive areas from the safety threshold; Optimize the weighting coefficients for the region; The maximum contact pressure in region K; This is the regional security threshold; This represents all regions defined on the inner surface of the prosthesis socket model.

[0093] The force model for the pressure-tolerant targets (PT, AMT, ALT, PD) can be expressed as:

[0094]

[0095] in, It is a weighted sum of squared deviations between the actual pressure and the safety threshold in all tolerance zones; This is the integral of the reaction force in the vertical direction; This is the integral of the tangential frictional force; These are biomechanical reference values.

[0096] Let the set of coordinates of the mesh nodes on the inner surface of the receiving cavity be P = {p1, p2, ..., pN}, and the objective function be F(P). The Shape-controller algorithm updates the node positions by solving the following gradient optimization problem:

[0097]

[0098] in:

[0099] The gradient of the objective function (sensitivity matrix) is calculated using the adjoint method:

[0100]

[0101] K is the stiffness matrix, R is the residual vector, and λ is the adjoint vector.

[0102] H is an approximation of the Hessian matrix to accelerate convergence.

[0103] P represents the original coordinate space position of the node, and ΔP represents the node displacement increment vector, which must satisfy the mesh quality constraint:

[0104]

[0105] Among them, Q min This indicates the lower limit of optimized mesh quality.

[0106] The overall comfort of the prosthetic socket model can be determined based on the contact pressure of the grid surface in each pressure-sensitive region, the force constraint of the grid in each pressure-sensitive region, the contact pressure of the grid surface in each pressure-resistant region, and the force constraint of the grid in each pressure-resistant region. In one or more embodiments, the overall comfort of the prosthetic socket model is negatively correlated with the mean square error of the difference between the contact pressure of the grid surface in each region and the corresponding force constraint; that is, the overall comfort of the prosthetic socket model is maximized when the mean square error of the difference between the contact pressure of the grid surface in each region and the corresponding force constraint is 0.

[0107] Step S110. When the iteration stopping condition is reached, the inner wall shape of the prosthetic socket model is adjusted based on the displacement increment of the grid surface in each pressure-sensitive region and the displacement increment of the grid surface in each pressure-tolerant region to obtain the PTB socket model for the lower leg amputee.

[0108] During iterative optimization, based on the contact pressure of the mesh surface in each pressure-sensitive region and the contact pressure of the mesh surface in each pressure-tolerant region, and ensuring that the contact pressure of the mesh in each pressure-sensitive region is less than or equal to its corresponding force constraint, the displacement increment of the mesh surface in each pressure-sensitive region and the displacement increment of the mesh surface in each pressure-tolerant region are adjusted. This adjustment is continued until the iteration stops. Then, based on the displacement increments of the mesh surfaces in each pressure-sensitive region and each pressure-tolerant region, the inner wall shape of the prosthetic socket model is adjusted to obtain the PTB socket model for the lower leg amputee patient.

[0109] The iteration stopping condition can be that the overall comfort level of the prosthetic socket model exceeds a pre-set comfort threshold. Let the optimal Morphing variable obtained through optimization be... The measured pressure in the area was Pmeas.

[0110] In one or more embodiments, after adjusting the inner wall shape of the prosthetic socket model based on the displacement increment of the grid surface in each pressure-sensitive region and the displacement increment of the grid surface in each pressure-resistant region, the inner wall of the prosthetic socket model can also be smoothed.

[0111] After obtaining the PTB socket model from the patient with lower leg amputation, the PTB socket model can be printed using a 3D printer to complete the optimized design of the PTB socket.

[0112] In summary, the PTB socket model optimization design method provided by this invention divides the inner surface of the prosthetic socket model into pressure-sensitive and pressure-tolerant regions. It simulates the maximum ground reaction force applied to a single leg during walking with a prosthesis in a lower leg amputee. Then, with the goal of maximizing the overall comfort of the prosthetic socket model, the displacement increment of the grid surface in each pressure-tolerant region is iteratively optimized using an optimization algorithm. This allows for optimized design tailored to the individual differences of lower leg amputees, avoiding stress concentration in sensitive areas and insufficient support in tolerance areas. This prevents discomfort, pain, or even secondary injury to lower leg amputees, improving their user experience. Furthermore, it enables automatic optimization design of the PTB socket, improving design efficiency and facilitating practical application and promotion.

[0113] Please refer to Figure 2. A second aspect of this application provides a PTB receiver cavity model optimization design apparatus, which includes:

[0114] The first building unit is used to construct a soft tissue model of the residual limb of a patient with lower leg amputation.

[0115] The second construction unit is used to construct an inner liner model and a prosthesis socket model based on the residual limb soft tissue model.

[0116] The construction and assembly unit is used to construct the connector model and assemble the residual limb soft tissue model, the inner liner model, the prosthesis receiving cavity model and the connector model to obtain the assembly model;

[0117] Mesh generation unit, used to perform mesh generation on the prosthesis socket model;

[0118] The coordinate system establishment unit is used to assign material properties to each model in the assembly model and to establish a coordinate system with the direction of the connector model toward the prosthesis receiving cavity model as the Z-axis direction.

[0119] The load application unit is used to apply a load to the bottom of the connector model under the condition of constraining the degree of freedom of the top cutting surface of the residual limb soft tissue model. The applied load is the maximum ground reaction force simulating the single-leg support when the lower leg amputee patient walks with a prosthesis.

[0120] A region division unit is used to divide the inner surface of the prosthesis socket model into multiple pressure-sensitive regions and multiple pressure-tolerant regions;

[0121] The stress model establishment unit is used to establish stress models of the grid surfaces in each pressure-sensitive region and the grid surfaces in each pressure-resistant region based on the load applied to the bottom of the connector model.

[0122] An iterative optimization unit is used to iteratively optimize the displacement increments of the grid surfaces in each pressure-sensitive region and each pressure-tolerant region based on the force constraints of the grid in each pressure-sensitive region and the force constraints of the grid in each pressure-tolerant region, with the goal of maximizing the overall comfort of the prosthetic socket model. The overall comfort of the prosthetic socket model is determined based on the contact pressure of the grid surfaces in each pressure-sensitive region, the force constraints of the grid in each pressure-sensitive region, the contact pressure of the grid surfaces in each pressure-tolerant region, and the force constraints of the grid in each pressure-tolerant region.

[0123] An adjustment unit is used to adjust the inner wall shape of the prosthetic socket model based on the displacement increment of the grid surface in each pressure-sensitive region and the displacement increment of the grid surface in each pressure-tolerant region when the iteration stopping condition is reached, so as to obtain the PTB socket model of the lower leg amputee patient.

[0124] The working process, working details and technical effects of the device provided in the second aspect of this embodiment can be found in the first aspect of the embodiment, and will not be repeated here.

[0125] As shown in Figure 3, a third aspect of this application provides an electronic device, including a memory, a processor, and a transceiver that are sequentially and communicatively connected. The memory is used to store a computer program, the transceiver is used to send and receive messages, and the processor is used to read the computer program and execute the PTB receiving cavity model optimization design method as described in the first aspect of the application.

[0126] Specifically, the memory may include, but is not limited to, random access memory (RAM), read-only memory (ROM), flash memory, first-in-first-out (FIFO) memory, and / or last-in-first-out (FILO) memory, etc.; the processor may not be limited to microprocessors of the STM32F105 series, ARM (Advanced RISC Machines), x86 architecture processors, or processors with integrated NPU (neural-network processing units); the transceiver may be, but is not limited to, WiFi (Wireless Fidelity) wireless transceivers, Bluetooth wireless transceivers, General Packet Radio Service (GPRS) wireless transceivers, ZigBee (a low-power LAN protocol based on the IEEE 802.15.4 standard), 3G transceivers, 4G transceivers, and / or 5G transceivers, etc.

[0127] This fourth aspect of the embodiment provides a computer-readable storage medium storing instructions containing the PTB receiver cavity model optimization design method described in the first aspect of the embodiment. Specifically, the computer-readable storage medium stores instructions that, when executed on a computer, perform the PTB receiver cavity model optimization design method as described in the first aspect. The computer-readable storage medium refers to a data storage medium, which may include, but is not limited to, floppy disks, optical disks, hard disks, flash memory, USB flash drives, and / or Memory Sticks. The computer may be a general-purpose computer, a special-purpose computer, a computer network, or other programmable devices.

[0128] The fifth aspect of this embodiment provides a computer program product containing instructions that, when executed on a computer, cause the computer to perform the PTB receiver cavity model optimization design method as described in the first aspect of the embodiment, wherein the computer may be a general-purpose computer, a special-purpose computer, a computer network, or other programmable device.

[0129] Finally, it should be noted that the above description is merely a preferred embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for optimizing the design of a PTB receiving cavity model, characterized in that, include: Constructing a soft tissue model of the residual limb from a patient with lower leg amputation; Based on the residual limb soft tissue model, construct an inner liner model and a prosthesis socket model; construct a connector model, and assemble the residual limb soft tissue model, the inner liner model, the prosthesis socket model, and the connector model to obtain an assembled model; The prosthesis socket model is meshed; Material properties are assigned to each model in the assembly model, and a coordinate system is established with the direction of the connector model toward the prosthesis socket model as the Z-axis direction. Under the constraint of the degrees of freedom of the top cut surface of the residual limb soft tissue model, a load is applied to the bottom of the connector model. The applied load is the maximum ground reaction force simulating the single-leg support when the lower leg amputee patient walks with a prosthesis. The inner surface of the prosthesis socket model is divided into multiple pressure-sensitive regions and multiple pressure-tolerant regions. Based on the load applied to the bottom of the connector model, force models of the grid surfaces in each pressure-sensitive region and each pressure-tolerant region are established. Based on the force constraints of the grids in each pressure-sensitive region and each pressure-tolerant region, with the goal of maximizing the overall comfort of the prosthesis socket model, the target is achieved. The optimization algorithm iteratively optimizes the displacement increments of the grid surfaces in each pressure-sensitive region and each pressure-tolerant region. The overall comfort of the prosthetic socket model is determined based on the contact pressure of the grid surfaces in each pressure-sensitive region, the force constraints of the grid in each pressure-sensitive region, the contact pressure of the grid surfaces in each pressure-tolerant region, and the force constraints of the grid in each pressure-tolerant region. When the iteration stops, the inner wall shape of the prosthetic socket model is adjusted based on the displacement increments of the grid surfaces in each pressure-sensitive region and each pressure-tolerant region to obtain the PTB socket model for the lower leg amputee patient.

2. The PTB receiving cavity model optimization design method according to claim 1, characterized in that, The construction of the soft tissue model of the residual limb of the lower leg amputee includes: acquiring CT scan images of the lower leg residual limb of the lower leg amputee; constructing a three-dimensional model of the lower leg residual limb based on the CT scan images; and smoothing the three-dimensional model of the lower leg residual limb to obtain the soft tissue model of the residual limb of the lower leg amputee.

3. The PTB receiving cavity model optimization design method according to claim 1, characterized in that, Constructing an inner liner model and a prosthesis socket model based on the residual limb soft tissue model includes: constructing the inner surface shape of the inner liner model based on the outer contour of the residual limb soft tissue model; increasing the inner surface shape of the inner liner model by a first specified thickness to obtain the inner liner model; constructing the inner surface shape of the prosthesis socket model based on the outer contour of the inner liner model; and increasing the inner surface shape of the prosthesis socket model by a second specified thickness to obtain the prosthesis socket model.

4. The PTB receiving cavity model optimization design method according to claim 1, characterized in that, The process of meshing the prosthetic socket model includes: performing 2D meshing on the prosthetic socket model; optimizing and adjusting the 2D mesh of the prosthetic socket model; and performing 3D tetrahedral meshing on the optimized and adjusted 2D mesh to obtain the 3D tetrahedral mesh of the prosthetic socket model.

5. The PTB receiving cavity model optimization design method according to claim 1, characterized in that, The material properties assigned to each model include density, elastic modulus, and / or Poisson's ratio.

6. The PTB receiving cavity model optimization design method according to claim 1, characterized in that, The plurality of pressure-sensitive areas include the tibial crest region, the fibular end region, the fibular head region, and / or the tibial end region, and the plurality of pressure-tolerant areas include the patellar tendon region, the anteromedial tibial region, the anterolateral tibial region, and / or the popliteal fossa region.

7. The PTB receiving cavity model optimization design method according to claim 6, characterized in that, The overall comfort of the prosthetic socket model is negatively correlated with the mean square error of the difference between the contact pressure of the grid surface in each region and the corresponding force constraint.

8. A device for optimizing the design of a PTB receiving cavity model, characterized in that, include: The first building unit is used to construct a soft tissue model of the residual limb of a patient with lower leg amputation. The second construction unit is used to construct an inner liner model and a prosthesis socket model based on the residual limb soft tissue model. The construction and assembly unit is used to construct the connector model and assemble the residual limb soft tissue model, the inner liner model, the prosthesis receiving cavity model and the connector model to obtain the assembly model; Mesh generation unit, used to perform mesh generation on the prosthesis socket model; The coordinate system establishment unit is used to assign material properties to each model in the assembly model and to establish a coordinate system with the direction of the connector model toward the prosthesis receiving cavity model as the Z-axis direction. The load application unit is used to apply a load to the bottom of the connector model under the condition of constraining the degree of freedom of the top cutting surface of the residual limb soft tissue model. The applied load is the maximum ground reaction force of single-leg support when the lower leg amputee patient walks with a prosthesis. The region division unit is used to divide the inner surface of the prosthesis socket model into multiple pressure-sensitive regions and multiple pressure-tolerant regions. The stress model establishment unit is used to establish stress models of the grid surfaces in each pressure-sensitive region and the grid surfaces in each pressure-resistant region based on the load applied to the bottom of the connector model. An iterative optimization unit is used to iteratively optimize the displacement increments of the grid surfaces in each pressure-sensitive region and each pressure-tolerant region based on the force constraints of the grid surfaces in each pressure-sensitive region and with the goal of maximizing the overall comfort of the prosthetic socket model. The overall comfort of the prosthetic socket model is determined based on the contact pressure of the grid surfaces in each pressure-sensitive region, the force constraints of the grid surfaces in each pressure-tolerant region, and the force constraints of the grid surfaces in each pressure-tolerant region. An adjustment unit is used to adjust the inner wall shape of the prosthetic socket model based on the displacement increments of the grid surfaces in each pressure-sensitive region and each pressure-tolerant region when the iteration stopping condition is met, thereby obtaining the PTB socket model for the lower leg amputee patient.

9. An electronic device, characterized in that, The device includes a memory, a processor, and a transceiver that are sequentially and communicatively connected. The memory is used to store a computer program, the transceiver is used to send and receive messages, and the processor is used to read the computer program and execute the PTB receiving cavity model optimization design method as described in any one of claims 1 to 7.

10. A computer program product, comprising a computer program or instructions, characterized in that, When the computer program or the instructions are executed by the computer, they implement the PTB receiver cavity model optimization design method as described in any one of claims 1 to 7.

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