A multi-scale simulation method for human lung blast injury

Abstract

The present invention provides a multi-scale simulation method for human lung explosion injury, which relates to the field of data processing technology. The method includes: constructing a chest wall model at a macroscopic scale based on the principle of dynamics; constructing an alveolar model at a microscopic scale based on the Euler-Lagrange fluid-solid coupling algorithm; setting the shock wave pressure when the explosion is transmitted to the human body; loading the shock wave pressure when the explosion is transmitted to the human body into the chest wall model, and solving it to determine the chest wall displacement under the action of the shock wave; loading the chest wall displacement into the alveolar model as an initial condition to analyze the deformation and damage of the human alveoli. In the present invention, a multi-scale simulation is performed on human lung explosion injury, the lung injury mechanism is revealed from a microscopic scale, the impact of explosion injury on the lung is simulated comprehensively and accurately, and the accuracy of lung loss prediction in an explosion environment is improved, which can provide a reference for rapid assessment of personnel injuries and treatment and protection.

Description

Technical Field

[0001] The present invention relates to the technical field of data processing, and in particular to a multi-scale simulation method and system for human lung explosion injury. Background Art

[0002] In an explosion incident, quickly predicting and assessing the severity of lung damage can help medical staff take effective treatment measures in a timely manner and save lives. Therefore, predicting human lung damage is of great significance.

[0003] Current multi-scale simulations of human lung explosion injuries often only analyze the relationship between shock waves and the lungs at the macroscopic level, but lack detailed analysis of the lung's microstructure, such as the alveoli. This restricts the revelation of the lung injury mechanism from a microscopic scale, making it difficult to fully and accurately simulate the impact of explosion injuries on the lungs, affecting the accuracy of lung loss prediction in an explosive environment. Summary of the invention

[0004] In order to solve the technical problem that the existing technology for multi-scale simulation of human lung explosion injury often only analyzes the relationship between shock waves and lungs at the macro level, but lacks detailed analysis of the microstructure of the lung, such as alveoli, which restricts the revelation of the lung injury mechanism from the microscopic scale, makes it difficult to fully and accurately simulate the impact of explosion injury on the lung, and affects the accuracy of lung loss prediction under explosion environment, the present invention provides a multi-scale simulation method and system for human lung explosion injury.

[0005] The technical solution provided by the embodiment of the present invention is as follows:

[0006] First aspect

[0007] An embodiment of the present invention provides a multi-scale simulation method for human lung explosion injury, comprising:

[0008] S1: Based on the principle of dynamics, a chest wall model is constructed at a macroscopic scale;

[0009] S2: Based on the Euler-Lagrange fluid-structure interaction algorithm, a microscopic alveolar model is constructed;

[0010] S3: Set the shock wave pressure when the explosion is transmitted to the human body;

[0011] S4: loading the shock wave pressure when the explosion is transmitted to the human body into the chest wall model, and solving it to determine the chest wall displacement under the shock wave;

[0012] S5: Loading the chest wall displacement as an initial condition into the alveolar model to analyze the deformation and damage of the human alveoli.

[0013] Second aspect

[0014] The embodiment of the present invention provides a multi-scale simulation system for human lung explosion injury, comprising:

[0015] processor;

[0016] A memory having computer-readable instructions stored thereon, wherein when the computer-readable instructions are executed by the processor, the multi-scale simulation method for human lung blast injury as described in the first aspect is implemented.

[0017] The third aspect

[0018] An embodiment of the present invention provides a computer-readable storage medium, on which a computer program is stored. When the program is executed by a processor, the multi-scale simulation method for human lung blast injury as described in the first aspect is implemented.

[0019] The beneficial effects brought about by the technical solution provided by the embodiment of the present invention include at least:

[0020] In the present invention, not only a chest wall model is constructed at a macroscopic scale, but also an alveolar model is constructed at a microscopic scale. The shock wave pressure when the explosion is transmitted to the human body is loaded into the chest wall model and solved to determine the chest wall displacement under the shock wave. The chest wall displacement is then loaded into the alveolar model as an initial condition to analyze the deformation and damage of the human alveoli, reveal the lung injury mechanism from a microscopic scale, comprehensively and accurately simulate the impact of explosion injuries on the lungs, and improve the accuracy of lung loss prediction in an explosion environment, which can provide a reference for rapid assessment of personnel injuries and treatment and protection. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0022] Figure 1 A schematic diagram of a flow chart of a multi-scale simulation method for human lung blast injury provided by an embodiment of the present invention;

[0023] Figure 2 A schematic diagram of the structure of a multi-scale simulation method for human lung blast injury provided by an embodiment of the present invention;

[0024] Figure 3 A schematic structural diagram of a multi-scale simulation system for human lung blast injury provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0025] The technical solution of the present invention is described below in conjunction with the accompanying drawings.

[0026] In the embodiments of the present invention, words such as "exemplarily" and "for example" are used to indicate examples, illustrations or explanations. Any embodiment or design described as "example" in the present invention should not be interpreted as being more preferred or more advantageous than other embodiments or designs. Specifically, the use of the word "example" is intended to present the concept in a specific way. In addition, in the embodiments of the present invention, the meaning expressed by "and / or" can be both, or it can be either of the two.

[0027] In the embodiments of the present invention, "image" and "picture" can sometimes be used interchangeably. It should be noted that when the difference between them is not emphasized, the meanings they intend to express are the same. "of", "corresponding, relevant" and "corresponding" can sometimes be used interchangeably. It should be noted that when the difference between them is not emphasized, the meanings they intend to express are the same.

[0028] In the embodiments of the present invention, sometimes the subscripts such as W 1 It may be written in non-subscript form such as W1. When the difference is not emphasized, the meaning is the same.

[0029] In order to make the technical problems, technical solutions and advantages to be solved by the present invention more clear, a detailed description will be given below with reference to the accompanying drawings and specific embodiments.

[0030] Reference Manual Attached Figure 1 , showing a schematic flow chart of a multi-scale simulation method for human lung blast injury provided by an embodiment of the present invention.

[0031] Reference Manual Attached Figure 2 , showing a structural schematic diagram of a multi-scale simulation method for human lung blast injury provided by an embodiment of the present invention.

[0032] The embodiment of the present invention provides a multi-scale simulation method for human lung explosion injury, which can be implemented by a multi-scale simulation device for human lung explosion injury, and the multi-scale simulation device for human lung explosion injury can be a terminal or a server. The processing flow of the multi-scale simulation method for human lung explosion injury can include the following steps:

[0033] S1: Based on the principles of dynamics, a chest wall model is constructed at a macroscopic scale.

[0034] Optionally, the human chest is simplified into a multi-layer composite medium including muscles, chest wall, and lungs in the front-to-back and left-to-right directions, the muscles are equivalent to spring-damper units, the chest wall is equivalent to mass units, and the lungs are equivalent to spring-damper units of viscoelastic porous structures to construct a chest wall model at a macro scale.

[0035] According to the dynamic model of chest wall velocity response and Newton's second law, the chest wall velocity response motion equations are constructed.

[0036] In a possible implementation, the chest wall velocity response motion equation group is specifically:

[0037]

[0038] Among them, M f represents the mass of the anterior chest wall, d represents the differential sign, X 1 represents the displacement of the anterior chest wall, t represents time, K 12 represents the elastic coefficient of the lung in the anterior-posterior direction, X 2 represents the posterior chest wall displacement, J 12 A represents the viscosity coefficient of the lung in the front-to-back direction. f represents the cross-sectional area of ​​the anterior chest wall, p 1w represents the forward pressure generated by the compressible gas in the lungs, p 12 Indicates the pressure in the front and back direction of the lung cavity, K 3 represents the elastic coefficient of the chest muscle, X 3 represents the displacement of the anterior chest muscles, J 3 Represents the viscosity coefficient of the chest muscle, M b represents the mass of the posterior chest wall, A b represents the cross-sectional area of ​​the posterior chest wall, p 2w Indicates the backward pressure generated by the compressible gas in the lungs, K 4 represents the elastic coefficient of the posterior chest muscle, X 4 represents the displacement of the posterior chest muscles, J 4 represents the viscosity coefficient of the posterior thoracic muscle, p f represents the forward explosion shock wave pressure, p b Represents the backward explosion shock wave pressure, M l represents the left chest wall mass, X 5 represents the displacement of the left chest wall, K 56 represents the elastic coefficient of the lung in the left and right directions, X 6 represents the right chest wall displacement, J 56 Represents the viscosity coefficient of the lung in the left and right directions, A l represents the cross-sectional area of ​​the left chest wall, p 5w Indicates the leftward pressure generated by the compressible gas in the lungs, p 56 Indicates the pressure in the left and right directions of the lung cavity, K 7 represents the elastic coefficient of the left chest muscle, X7 represents the displacement of the left pectoral muscle, J 7 represents the viscosity coefficient of left pectoral muscle, M r represents the right chest wall mass, A r represents the cross-sectional area of ​​the right chest wall, p 6w Indicates the rightward pressure generated by the compressible gas in the lungs, K 8 represents the elastic coefficient of the right chest muscle, X 8 represents the displacement of the right pectoral muscle, J 8 represents the viscosity coefficient of the right pectoral muscle, p l Indicates the leftward explosion shock wave pressure, p r Indicates the rightward explosion shock wave pressure.

[0039] In the present invention, by constructing a group of motion equations based on the chest wall velocity response dynamics model and Newton's second law, a systematic mechanical description can be provided, the accuracy and reliability of the model can be improved, complex dynamic behaviors can be captured, numerical solutions and simulations can be facilitated, and multi-directional and multi-level analysis can be supported, providing a basis for personalized protection recommendations and interdisciplinary research. These benefits make this method of great theoretical and practical significance in the prediction of human lung injury under the action of explosion shock waves.

[0040] Optionally, the forward pressure, backward pressure, leftward pressure and rightward pressure generated by the compressible gas in the lungs are specifically:

[0041]

[0042] Among them, p 1w represents the forward pressure generated by the compressible gas in the lungs, p 0 It represents the pressure of the lung cavity when it is not affected by the explosion shock wave, c 0 represents the speed of sound when the lung cavity is not affected by the explosion shock wave, γ represents the gas constant, and p 2w Indicates the backward pressure generated by the compressible gas in the lungs, p 5w Indicates the leftward pressure generated by the compressible gas in the lungs, p 6w Indicates the rightward pressure generated by the compressible gas in the lungs.

[0043] In the present invention, the pressure of the compressible gas in the lungs in all directions is concretized, which can more realistically reflect the stress condition of the lung tissue under the action of the explosion shock wave and ensure that the model results are closer to reality.

[0044] Optionally, the pressure in the front-to-back direction and the pressure in the left-to-right direction of the lung cavity are specifically:

[0045]

[0046] ΔX 12 =X 1 -X2

[0047]

[0048] ΔX 56 =X 5 -X 6

[0049] Among them, p 12 Indicates the pressure in the front and back direction of the lung cavity, p 0 It represents the pressure of the lung cavity when it is not affected by the explosion shock wave, V represents the volume of the lung cavity, ΔV 12 Indicates the volume change of the lung cavity in the front-to-back direction, D 12 Indicates the distance in the front and back direction of the lung cavity, ΔX 12 Indicates the displacement change of lung cavity in the front and back direction, p 56 Indicates the pressure in the left and right directions of the lung cavity, ΔV 56 Indicates the volume change of the lung cavity in the left and right directions, D 56 Indicates the distance from the lung cavity to the left and right, ΔX 56 Indicates the change in displacement of the lung cavity in the left and right directions.

[0050] In the present invention, the dynamic response of the lung cavity under the action of the explosion shock wave can be captured through the embodied pressure calculation, including the instantaneous pressure change and the continuous pressure effect, so as to support dynamic analysis and prediction.

[0051] S2: Based on the Euler-Lagrange fluid-structure interaction algorithm, a microscopic alveolar model is constructed.

[0052] Among them, the Euler-Lagrange fluid-solid coupling algorithm combines the fluid dynamics described by Euler and the solid mechanics described by Lagrange, and realizes the coupling of fluid and solid at the fluid-solid interface through the finite element method (FEM).

[0053] In a possible implementation, S2 specifically includes:

[0054] S201: Construct alveolar geometric model.

[0055] The alveolar geometric model includes: the alveolar wall as a solid part and the air as a fluid part.

[0056] S202: Describe the solid part under the Lagrange framework.

[0057] Optionally, S202 specifically includes:

[0058] In the Lagrange framework, the stress tensor of the solid part is described according to the following formula:

[0059] Ps (ε s )=F(ε s )S(ε s )

[0060] Among them, P s represents the first-order Piola-Kirchhoff solid stress tensor, ε s represents the solid displacement, F represents the deformation gradient, and S represents the second Piola-Kirchhoff stress tensor.

[0061] It should be noted that the Lagrange framework uses the initial configuration as a reference, which means that no matter how large the deformation of the solid is, the quantity described is referenced to the initial state, and can accurately capture and describe nonlinear geometric effects in large deformations, which is especially important for biological structures such as alveolar walls that may undergo significant deformation.

[0062] Optionally, the deformation gradient is specifically:

[0063]

[0064] Where I represents the identity matrix, Represents a gradient operation.

[0065] Optionally, the second Piola-Kirchhoff stress tensor is specifically:

[0066] S(ε s )=λ s tr(E(ε s ))I+2μ s E(ε s )

[0067] Among them, λ s represents the Lame constant, tr represents the matrix rank operation, E represents the Green-Lagrange strain tensor, μ s represents the shear modulus.

[0068] Optionally, the Green-Lagrange strain tensor is specified as:

[0069]

[0070] in, T Represents a matrix transpose operation.

[0071] It should be noted that the use of the second Piola-Kirchhoff stress tensor and Green-Lagrange strain tensor can maintain the integrity of material properties. The second Piola-Kirchhoff stress and Green-Lagrange strain are closely related to the properties of the alveolar wall itself in a physical sense, especially when describing the behavior of nonlinear objects. This method can better reflect the true stress-strain relationship of the alveolar wall during deformation.

[0072] S203: Preliminary description of the fluid part under the Euler framework.

[0073] Optionally, S203 specifically includes:

[0074] In the Euler framework, the dynamic equation of the fluid part is preliminarily described according to the following formula:

[0075]

[0076] Where u represents the fluid velocity, t represents the time, represents the partial derivative operation, represents the gradient operation, σ represents the fluid stress tensor, and p f Indicates fluid pressure.

[0077] It should be noted that the Euler framework uses the current configuration as a reference, so it is more suitable for describing media such as fluids that have significant deformation and movement. During the flow of a fluid, the relative position and velocity of its various parts will continue to change. The Euler description can directly track and calculate the changes in the velocity field and pressure field of the fluid over time.

[0078] Optionally, the fluid stress tensor is specifically:

[0079]

[0080] Where Re represents the fluid Reynolds number, and T represents the matrix transpose operation.

[0081] S204: Introduce fluid deformation parameters into the fluid part, propagate the solid displacement at the fluid-solid interface into the fluid through the fluid deformation parameters, and describe the fluid part in detail.

[0082] It should be noted that the introduction of fluid deformation parameters enables the fluid part to more accurately reflect the deformation and movement of the solid at the fluid-solid interface. This coupling can capture the effect of solid deformation on fluid flow, thereby improving the accuracy of the simulation.

[0083] Optionally, S204 specifically includes:

[0084] The fluid deformation parameters of the fluid part are introduced to propagate the solid displacement at the fluid-solid interface into the fluid, and to accurately describe the stress tensor of the fluid part:

[0085] P f (ε f )=σ c (u,p f ,ε f )Φ(ε f ) T

[0086] Among them, P f represents the first-order Piola-Kirchhoff fluid stress tensor, ε f represents the fluid deformation parameter, σ c represents the Cauchy stress tensor, u represents the fluid velocity, and p f represents the fluid pressure, Φ represents the deformation, T Represents a matrix transpose operation.

[0087] Optionally, the Cauchy stress tensor is specified as:

[0088]

[0089] Where I represents the identity matrix, Re represents the fluid Reynolds number, and J represents the transformation Jacobian matrix.

[0090] Optionally, the deformation amount is specifically:

[0091]

[0092] It should be noted that for fluid-solid coupling problems with obvious nonlinear deformation, the use of fluid deformation parameters can more naturally handle geometric nonlinear effects. The calculation of deformation and transformation Jacobian matrix enables the fluid part to adapt to the complex geometric changes caused by solid deformation.

[0093] Optionally, the fluid deformation parameters satisfy:

[0094]

[0095] Among them, ε f represents the fluid deformation parameter, Θ represents the extension operator, and the extension operator is specifically the Laplace equation.

[0096] It should be noted that by setting the fluid deformation parameters to meet the above conditions, the volume conservation of the fluid is ensured during the fluid-solid interaction process. Laplace's equation is usually used to describe divergence-free fields, that is, to ensure that the volume of the fluid remains unchanged during the deformation process. This is very important for simulating real fluid behavior, especially when incompressible fluids are involved.

[0097] S205: Through the embedded boundary method, the fluid part and the solid part are coupled to construct an alveolar model at the microscopic scale.

[0098] It should be noted that the embedded boundary method allows accurate simulation of the continuity of physical quantities at the fluid-solid interface. Ensuring the continuity of displacement, velocity, and stress can more accurately describe the interaction between fluid and solid.

[0099] Optionally, S205 specifically includes:

[0100] Through the embedded boundary method, the displacement continuity, velocity continuity and stress continuity are guaranteed on the fluid-solid interface, and the fluid part and the solid part are coupled.

[0101] The displacement continuity is specifically:

[0102] ε f =ε s

[0103] Among them, ε f represents the fluid deformation parameter, ε s Represents the displacement of the solid.

[0104] Speed ​​continuity is as follows:

[0105]

[0106] Where u represents the fluid velocity, represents partial derivative operation, and t represents time.

[0107] The stress continuity is specifically:

[0108] n·P f (ε f )=n·P s (ε s )

[0109] Where n represents the normal vector of the fluid-solid interface, P f represents the first-order Piola-Kirchhoff fluid stress tensor, P s represents the first-order Piola-Kirchhoff solid stress tensor.

[0110] It should be noted that ensuring displacement continuity, velocity continuity and stress continuity can truly reproduce the physical interaction between fluid and solid. At the fluid-solid interface, the interaction between fluid and solid will affect the flow, deformation and force transmission of the material. Maintaining the continuity condition is the basic requirement for simulating these interactions.

[0111] In the present invention, a microscopic alveolar model is constructed based on the Euler-Lagrange fluid-solid coupling algorithm, which can comprehensively and accurately simulate and analyze the mechanical response of the alveoli under different external impacts, reveal the microscopic mechanism of lung injury, and provide important theoretical and technical support for related research and applications.

[0112] S3: Sets the shock wave pressure when the explosion is transmitted to the human body.

[0113] S4: Load the shock wave pressure when the explosion is transmitted to the human body into the chest wall model and solve it to determine the chest wall displacement under the action of the shock wave.

[0114] Optionally, the above chest wall velocity response motion equations are solved by a Newmark-beta algorithm.

[0115] Specifically, the shock wave pressure when the explosion is transmitted to the human body is loaded into the chest wall velocity response motion equation group, and the forward explosion shock wave pressure p at the chest wall position can be determined. f , backward explosion shock wave pressure p b , leftward explosion shock wave pressure p l And the rightward explosion shock wave pressure p r Then, the chest wall velocity response motion equations are used to simultaneously solve the initial As the initial solution of the Newmark-beta algorithm.

[0116] Afterwards, the displacement and velocity of the next time step can be predicted based on the displacement, velocity, and acceleration of the current time step:

[0117]

[0118] Among them, X i represents chest wall displacement, i=1,2,5,6, X 1 represents the displacement of the anterior chest wall, X 2 represents the posterior chest wall displacement, X 5 represents the displacement of the left chest wall, X 6 Indicates right chest wall displacement, represents the predicted value of chest wall displacement at time t+1, represents the chest wall displacement at time t, Δt represents the time step, d represents the differential sign, β represents the displacement iteration parameter, and γ represents the velocity iteration parameter.

[0119] The predicted displacement and velocity are substituted into the chest wall velocity response motion equations to solve for the acceleration at the next time step.

[0120] According to the acceleration of the next time step, the displacement and velocity of the next time step are corrected:

[0121]

[0122] in, represents the chest wall displacement at time t+1.

[0123] The above iterative process is repeated to determine the chest wall displacement under the action of the shock wave.

[0124] Among them, the Newmark-beta method is an implicit integration method with unconditional stability. It can maintain numerical stability under larger time steps and avoid numerical divergence during the calculation process.

[0125] In the present invention, the chest wall velocity response motion equations are solved by the Newmark-beta algorithm, which can improve numerical stability and accuracy, adapt to nonlinear and complex systems, capture dynamic responses, provide prediction and correction mechanisms, provide complete mechanical response data, facilitate numerical implementation and expansion, and improve the adaptability and versatility of the model.

[0126] S5: The chest wall displacement is loaded into the alveolar model as the initial condition to analyze the deformation and damage of the human alveoli.

[0127] It should be noted that the displacement of the chest wall has an important influence on the mechanical behavior of the alveoli through the change of intrathoracic pressure and the transmission of the pleura. In numerical simulation, taking the chest wall displacement as the initial condition can effectively capture this indirect mechanical coupling effect, thereby accurately simulating the deformation and mechanical response of the alveoli under different conditions.

[0128] In a possible implementation, S5 specifically includes: loading the chest wall displacement as an initial condition into the alveolar model, and analyzing the deformation and damage of the human alveoli by using the finite element analysis method.

[0129] Among them, finite element analysis is a numerical calculation method used to solve boundary value problems in physics and engineering. It divides a complex continuous domain into a finite number of smaller and simpler units, analyzes each unit, and finally combines the results to solve the response of the entire domain.

[0130] In a possible implementation, S5 specifically includes sub-steps S501 to S506:

[0131] S501: Meshing the alveolar model.

[0132] Optionally, the grid form may be a triangle, a square or a hexagon.

[0133] It should be noted that by constructing an alveolar model at the microscale and performing meshing, the stress and strain distribution in the alveoli can be analyzed in detail. This level of detail analysis can reveal the damage characteristics and possible damage mechanisms of the local area, providing more accurate results than macroscale analysis.

[0134] S502: Discretize the fluid part.

[0135] Optionally, S502 specifically includes: discretizing the fluid part according to the following formula:

[0136]

[0137] Among them, Ω f represents the partial volume of the fluid, represents the gradient operation, σ represents the fluid stress tensor, u represents the fluid velocity, p f Indicates fluid pressure, P f represents the first-order Piola-Kirchhoff fluid stress tensor, ε f represents the fluid deformation parameter, Ψ f represents the fluid test function, d represents the differential operation, Γ represents the fluid-solid interface, : represents the inner product operation, and λ represents the Lagrange multiplier.

[0138] It should be noted that discretization allows complex fluid dynamics equations to be solved on a limited number of computing nodes, which makes it feasible to use computers to solve them, thereby accurately describing the field distribution of fluid velocity, pressure, etc.

[0139] S503: Discretize the solid part.

[0140] Optionally, S503 specifically includes: discretizing the solid part according to the following formula:

[0141]

[0142] Among them, Ω s represents the solid part volume, P s represents the first-order Piola-Kirchhoff solid stress tensor, ε s represents the alveolar wall displacement, Ψ s Represents a solid test function.

[0143] S504: Summarize the stress tensors of each point on the grid and construct a global stress tensor equation group.

[0144] Among them, the global stress tensor equations can reflect the relationship between the stress tensors of each point on the grid. The alveolar model is divided into multiple small grid units (such as triangles, squares or hexagons). At the nodes of each grid unit, local stresses and strains are calculated. The stress tensor is a matrix that describes the distribution of internal forces and reflects the forces in all directions in a specific area. Through mesh discretization, the local equations of fluid and solid have solved the local stress and strain on each grid unit. The goal of the global stress tensor equation is to summarize these local equations through the finite element method to form the stress equilibrium equation of the overall system. In each unit, we get the local stress tensor and the corresponding displacement field. In the finite element method, these local results need to be "assembled" into the global system equations. By summarizing the stress and displacement equations of all grid units, a global stiffness matrix is ​​formed. Once the global stiffness matrix is ​​assembled, the linear equations can be solved by numerical methods (such as iterative solvers or direct solvers) to finally obtain the global displacement field. After the displacement field is obtained, the stress distribution at each grid point in the alveolar is further calculated through the stress-strain relationship.

[0145] By summarizing the stress tensors at each point on the mesh, a global stress tensor equation set for the entire system can be constructed. This helps to accurately reflect the mechanical behavior of the entire alveolar model under the action of external boundary conditions. The solution of the global equation set can capture the stress distribution and deformation characteristics in the entire model.

[0146] S505: Taking the chest wall displacement as the initial condition, deriving the displacement distribution of the alveolar wall, substituting it into the global stress tensor equation group, and solving the global stress tensor equation group to obtain the stress tensor at each location of the alveolar model.

[0147] Using chest wall displacement as the initial condition to derive the displacement distribution of the alveolar wall and substituting it into the global stress tensor equations can make the solution process closer to the actual situation. Such boundary conditions reflect the impact of the external environment on the system and are important inputs for solving the equations and analyzing the system response. By accurately setting these boundary conditions, the accuracy and reliability of the simulation results can be improved.

[0148] Specifically, the chest wall displacement can be used as the initial condition to convert the pressure change in the chest cavity into the stress on the alveolar wall. By solving the equilibrium equation of elastic mechanics and combining appropriate boundary conditions (such as pressure boundary conditions or displacement boundary conditions), the displacement distribution of the alveolar wall can be obtained.

[0149] S506: Analyze the deformation and damage of human alveoli according to the stress tensors at various locations of the alveolar model.

[0150] Optionally, S506 specifically includes:

[0151] The area in the alveolar model where the stress tensor is greater than the preset stress tensor is determined as the damaged area.

[0152] Among them, those skilled in the art can set the size of the preset stress tensor according to actual conditions, and the present invention does not limit this.

[0153] The proportion of the damaged area to the total area is calculated as the damage value:

[0154]

[0155] Where τ represents the damage value, S a represents the area of ​​the damaged area, S tot Indicates the total area.

[0156] According to the damage value, the deformation and damage of human alveoli are analyzed.

[0157] It should be noted that the damage value τ provides a quantitative indicator to evaluate the degree of damage to the alveoli under certain conditions (such as external impact or pressure). A higher damage value means that a larger proportion of the alveolar area is damaged, indicating more serious potential damage. It can reveal the mechanism of lung injury from a microscopic scale, comprehensively and accurately simulate the impact of explosion injury on the lungs, improve the accuracy of lung loss prediction in an explosive environment, and provide a reference for rapid assessment of personnel injuries and treatment and protection.

[0158] The beneficial effects brought about by the technical solution provided by the embodiment of the present invention include at least:

[0159] In the present invention, not only a chest wall model is constructed at a macroscopic scale, but also an alveolar model is constructed at a microscopic scale. The shock wave pressure when the explosion is transmitted to the human body is loaded into the chest wall model and solved to determine the chest wall displacement under the shock wave. The chest wall displacement is then loaded into the alveolar model as an initial condition to analyze the deformation and damage of the human alveoli, reveal the lung injury mechanism from a microscopic scale, comprehensively and accurately simulate the impact of explosion injuries on the lungs, and improve the accuracy of lung loss prediction in an explosive environment, which can provide a reference for rapid assessment of personnel injuries and treatment and protection.

[0160] Reference Manual Attached Figure 3 , showing a schematic structural diagram of a multi-scale simulation system for human lung explosion injury provided by the present invention.

[0161] The present invention also provides a multi-scale simulation system 20 for human lung explosion injury, which is applied to the multi-scale simulation method for human lung explosion injury, and comprises:

[0162] Processor 201.

[0163] The memory 202 stores computer-readable instructions. When the computer-readable instructions are executed by the processor 201, a multi-scale simulation method for human lung explosion injury according to the method embodiment is implemented.

[0164] The multi-scale simulation system 20 for human lung explosion injury provided by the present invention can execute the above-mentioned multi-scale simulation method for human lung explosion injury and achieve the same or similar technical effects. To avoid repetition, the present invention will not go into details.

[0165] The beneficial effects brought about by the technical solution provided by the embodiment of the present invention include at least:

[0166] In the present invention, not only a chest wall model is constructed at a macroscopic scale, but also an alveolar model is constructed at a microscopic scale. The shock wave pressure when the explosion is transmitted to the human body is loaded into the chest wall model and solved to determine the chest wall displacement under the shock wave. The chest wall displacement is then loaded into the alveolar model as an initial condition to analyze the deformation and damage of the human alveoli, reveal the lung injury mechanism from a microscopic scale, comprehensively and accurately simulate the impact of explosion injuries on the lungs, and improve the accuracy of lung loss prediction in an explosion environment, which can provide a reference for rapid assessment of personnel injuries and treatment and protection.

[0167] It should be understood that the processor in the embodiment of the present invention may be a central processing unit (CPU), and the processor may also be other general-purpose processors, digital signal processors (DSP), application specific integrated circuits (ASIC), field programmable gate arrays (FPGA) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. The general-purpose processor may be a microprocessor or the processor may also be any conventional processor, etc.

[0168] It should also be understood that the memory in the embodiments of the present invention may be a volatile memory or a non-volatile memory, or may include both volatile and non-volatile memories. Among them, the non-volatile memory may be a read-only memory (ROM), a programmable read-only memory (PROM), an erasable programmable read-only memory (EPROM), an electrically erasable programmable read-only memory (EEPROM), or a flash memory. The volatile memory may be a random access memory (RAM), which is used as an external cache. By way of example and not limitation, many forms of random access memory (RAM) are available, such as static RAM (SRAM), dynamic random access memory (DRAM), synchronous DRAM (SDRAM), double data rate synchronous dynamic random access memory (DDR SDRAM), enhanced synchronous dynamic random access memory (ESDRAM), synchronous link DRAM (SLDRAM), and direct rambus RAM (DR RAM).

[0169] The above embodiments can be implemented in whole or in part by software, hardware (such as circuits), firmware or any other combination. When implemented by software, the above embodiments can be implemented in whole or in part in the form of a computer program product. The computer program product includes one or more computer instructions or computer programs. When the computer instructions or computer programs are loaded or executed on a computer, the process or function described in the embodiment of the present invention is generated in whole or in part. The computer can be a general-purpose computer, a special-purpose computer, a computer network, or other programmable device. The computer instructions can be stored in a computer-readable storage medium, or transmitted from one computer-readable storage medium to another computer-readable storage medium. For example, the computer instructions can be transmitted from one website, computer, server or data center to another website, computer, server or data center by wired (such as infrared, wireless, microwave, etc.). The computer-readable storage medium can be any available medium that can be accessed by a computer or a data storage device such as a server or data center that contains one or more available media sets. The available medium can be a magnetic medium (for example, a floppy disk, a hard disk, a tape), an optical medium (for example, a DVD), or a semiconductor medium. The semiconductor medium can be a solid-state hard disk.

[0170] It should be understood that the term "and / or" in this article is only a description of the association relationship of associated objects, indicating that there can be three relationships. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. A and B can be singular or plural. In addition, the character " / " in this article generally indicates that the associated objects before and after are in an "or" relationship, but it may also indicate an "and / or" relationship. Please refer to the context for specific understanding.

[0171] In the present invention, "at least one" means one or more, and "more than one" means two or more. "At least one of the following" or similar expressions refers to any combination of these items, including any combination of single or plural items. For example, at least one of a, b, or c can be represented by: a, b, c, ab, ac, bc, or abc, where a, b, c can be single or multiple.

[0172] It should be understood that in various embodiments of the present invention, the size of the serial numbers of the above-mentioned processes does not mean the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present invention.

[0173] Those skilled in the art will appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of the present invention.

[0174] Those skilled in the art can clearly understand that, for the convenience and brevity of description, the specific working processes of the above-described equipment, devices and units can refer to the corresponding processes in the aforementioned method embodiments and will not be repeated here.

[0175] In the several embodiments provided by the present invention, it should be understood that the disclosed devices, apparatuses and methods can be implemented in other ways. For example, the device embodiments described above are only schematic. For example, the division of the units is only a logical function division. There may be other division methods in actual implementation, such as multiple units or components can be combined or integrated into another device, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of devices or units, which can be electrical, mechanical or other forms.

[0176] The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed on multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0177] In addition, each functional unit in each embodiment of the present invention may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit.

[0178] If the functions are implemented in the form of software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention can be essentially or partly embodied in the form of a software product that contributes to the prior art. The computer software product is stored in a storage medium and includes several instructions for enabling a computer device (which can be a personal computer, a server, or a network device, etc.) to perform all or part of the steps of the methods described in various embodiments of the present invention. The aforementioned storage medium includes: various media that can store program codes, such as a USB flash drive, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk or an optical disk.

[0179] An embodiment of the present invention provides a computer-readable storage medium having a computer program stored thereon, wherein when the program is executed by a processor, the multi-scale simulation method for human lung blast injury as described in the method embodiment is implemented.

[0180] A computer-readable storage medium provided by the present invention can implement the steps and effects of the multi-scale simulation method for human lung blast injury of the above method embodiment. To avoid repetition, the present invention will not go into details.

[0181] The beneficial effects brought about by the technical solution provided by the embodiment of the present invention include at least:

[0182] In the present invention, not only a chest wall model is constructed at a macroscopic scale, but also an alveolar model is constructed at a microscopic scale. The shock wave pressure when the explosion is transmitted to the human body is loaded into the chest wall model and solved to determine the chest wall displacement under the shock wave. The chest wall displacement is then loaded into the alveolar model as an initial condition to analyze the deformation and damage of the human alveoli, reveal the lung injury mechanism from a microscopic scale, comprehensively and accurately simulate the impact of explosion injuries on the lungs, and improve the accuracy of lung loss prediction in an explosion environment, which can provide a reference for rapid assessment of personnel injuries and treatment and protection.

[0183] The above is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art can easily think of changes or substitutions within the technical scope disclosed by the present invention, which should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

[0184] There are a few points to note:

[0185] (1) The drawings of the embodiments of the present invention only relate to the structures related to the embodiments of the present invention, and other structures may refer to the general design.

[0186] (2) For the sake of clarity, in the drawings used to describe the embodiments of the present invention, the thickness of the layers or regions is exaggerated or reduced, that is, these drawings are not drawn according to the actual scale. It is understood that when an element such as a layer, film, region or substrate is referred to as being "on" or "under" another element, the element may be "directly" "on" or "under" the other element or there may be intermediate elements.

[0187] (3) In the absence of conflict, the embodiments of the present invention and the features therein may be combined with each other to obtain new embodiments.

[0188] The above are only specific embodiments of the present invention, but the protection scope of the present invention is not limited thereto. The protection scope of the present invention shall be based on the protection scope of the claims.

Claims

1. A multi-scale simulation method for human lung explosion injury, characterized in that: include: S1: Based on the principle of dynamics, a chest wall model is constructed at a macroscopic scale; S2: Based on the Euler-Lagrange fluid-structure interaction algorithm, a microscopic alveolar model is constructed; S3: Set the shock wave pressure when the explosion is transmitted to the human body; S4: loading the shock wave pressure when the explosion is transmitted to the human body into the chest wall model, and solving it to determine the chest wall displacement under the shock wave; S5: loading the chest wall displacement as an initial condition into the alveolar model to analyze the deformation and damage of the human alveoli; Wherein, the S2 specifically includes: S201: constructing an alveolar geometric model, wherein the alveolar geometric model includes: alveolar walls as a solid part and air as a fluid part; S202: describing the solid part under the Lagrange framework; S203: Preliminarily describing the fluid part under the Euler framework; S204: introducing a fluid deformation parameter into the fluid part, propagating the solid displacement at the fluid-solid interface into the fluid through the fluid deformation parameter, and precisely describing the fluid part; S205: The fluid part and the solid part are coupled by an embedded boundary method to construct an alveolar model at a microscopic scale.

2. The multi-scale simulation method for human lung explosion injury according to claim 1, characterized in that: The S202 is specifically as follows: In the Lagrange framework, the stress tensor of the solid part is described according to the following formula: P s (e s )=F(e s )S(e s ) Among them, P s represents the first-order Piola-Kirchhoff solid stress tensor, ε s represents the solid displacement, F represents the deformation gradient, and S represents the second Piola-Kirchhoff stress tensor; The deformation gradient is specifically: F(e s )=I+▽ε s Among them, I represents the identity matrix, ▽ represents the gradient operation; The second Piola-Kirchhoff stress tensor is specifically: S(e s )=λ s tr(E(e s ))I+2m s E(e s ) Among them, λ s represents the Lame constant, tr represents the matrix rank operation, E represents the Green-Lagrange strain tensor, μ s represents the shear modulus; The Green-Lagrange strain tensor is specifically: Wherein, T represents the matrix transpose operation.

3. The multi-scale simulation method for human lung explosion injury according to claim 1, characterized in that: The S203 is specifically as follows: In the Euler framework, the dynamic equation of the fluid part is preliminarily described according to the following formula: Where u represents the fluid velocity, t represents the time, represents the partial derivative operation, represents the gradient operation, σ represents the fluid stress tensor, and p f Indicates fluid pressure; The fluid stress tensor is specifically: Where Re represents the fluid Reynolds number, and T represents the matrix transpose operation.

4. The multi-scale simulation method for human lung explosion injury according to claim 1, characterized in that: The S204 is specifically as follows: The fluid deformation parameters of the fluid part are introduced to propagate the solid displacement at the fluid-solid interface into the fluid, and to accurately describe the stress tensor of the fluid part: P f (e f )=s c (u,p f ,he f )Φ(e f ) T Among them, P f represents the first-order Piola-Kirchhoff fluid stress tensor, ε f represents the fluid deformation parameter, σ c represents the Cauchy stress tensor, u represents the fluid velocity, and p f represents the fluid pressure, Φ represents the deformation, T Represents a matrix transpose operation; The Cauchy stress tensor is specifically: Where I represents the identity matrix, Re represents the fluid Reynolds number, and J represents the transformation Jacobian matrix; The deformation amount is specifically: The fluid deformation parameters satisfy: Among them, ε f represents the fluid deformation parameter, Θ represents the expansion operator, and the expansion operator is specifically the Laplace equation.

5. The multi-scale simulation method for human lung explosion injury according to claim 1, characterized in that: The S5 is specifically: The chest wall displacement is loaded into the alveolar model as an initial condition, and the deformation and damage of the human alveoli are analyzed by finite element analysis.

6. The multi-scale simulation method for human lung explosion injury according to claim 5, characterized in that: The S5 specifically includes: S501: Meshing the alveolar model; S502: discretizing the fluid part; S503: discretizing the solid part; S504: Summarize the stress tensors of each point on the grid and construct a global stress tensor equation group; S505: Using the chest wall displacement as an initial condition, deriving the displacement distribution of the alveolar wall, substituting it into the global stress tensor equation group, and solving the global stress tensor equation group to obtain the stress tensor at each location of the alveolar model; S506: Analyze the deformation and damage of the human alveoli according to the stress tensors at various locations of the alveolar model.

7. The multi-scale simulation method for human lung explosion injury according to claim 6, characterized in that: The S502 is specifically as follows: The fluid part is discretized according to the following formula: Among them, Ω f represents the fluid part, represents the gradient operation, σ represents the fluid stress tensor, u represents the fluid velocity, p f Indicates fluid pressure, P f represents the first-order Piola-Kirchhoff fluid stress tensor, ε f represents the fluid deformation parameter, Ψ f represents the fluid test function, d represents the differential operation, Γ represents the fluid-solid interface, : represents the inner product operation, and λ represents the Lagrange multiplier; The S503 is specifically as follows: The solid part is discretized according to the following formula: Among them, Ω s Represents the solid part, P s represents the first-order Piola-Kirchhoff solid stress tensor, ε s represents the alveolar wall displacement, Ψ s Represents a solid test function.

8. The multi-scale simulation method for human lung explosion injury according to claim 6, characterized in that: S506 specifically includes: Determining a region in the alveolar model where the stress tensor is greater than a preset stress tensor as a damaged region; Counting the ratio of the area of ​​the damaged area to the total area as the damage value; The deformation and damage of the human alveoli are analyzed according to the damage value.

Images