Intestinal tract flow field modeling method and device based on bidirectional fluid-solid coupling

Abstract

The invention discloses an intestinal tract flow field modeling method and device based on bidirectional fluid-solid coupling. The method comprises the following steps: S1, collecting intestinal tract multi-modal data; wherein the multi-modal data comprises geometric parameters, motion characteristics, content statistics and wall stress strain data of the intestinal tract; s2, performing three-dimensional reconstruction on a human body real intestinal tract geometric model; s3, performing preprocessing of format conversion and simplified modification on the established intestinal tract geometric model; s4, dividing the preprocessed model into a model fluid domain and a solid domain, and establishing a bidirectional fluid-solid coupling model architecture; s5, performing fluid domain simulation setting: simulating multiphase flow contents, and setting a fluid simulation model; s6, performing solid domain simulation setting: setting intestinal wall material parameters, and simulating intestinal movement; and S7, bidirectional fluid-solid coupling is realized, and an intestinal tract flow field is simulated. Bidirectional interaction between an intestinal tract wall solid domain and an intestinal tract content fluid domain is considered, and more accurate intestinal tract flow field simulation is achieved.

Description

Technical Field

[0001] The present invention belongs to the technical field of medical models, and in particular relates to a method and device for modeling an intestinal flow field based on bidirectional fluid-solid coupling. Background Art

[0002] Gastrointestinal diseases are one of the most common diseases in the world. An international multicenter study found that more than 40% of the world's population suffers from functional gastrointestinal diseases. Therefore, understanding the physiological state of the intestine is important for reducing the burden of related diseases. However, the physiological state of the intestine is complex and changeable, and there are significant differences in the intestinal flow field in different intestinal segments and at different times.

[0003] Numerical simulation, as a method of simulating complex medical phenomena using computer algorithms, is often used in the medical field to simulate hemodynamics and biomechanical behavior. Combining intestinal flow field with numerical simulation has become an important supplementary means to study processes such as digestion, absorption, and pH value changes in the intestine. The modeling of intestinal flow field can be significantly achieved through the method of computational fluid dynamics. However, in traditional intestinal flow field numerical simulation research, the impact of simulated intestinal wall movement on intestinal contents is usually limited, or the intestinal wall is set as an immovable rigid body, ignoring the impact of intestinal contents on the intestinal wall, and the simulation results are correspondingly biased. Summary of the invention

[0004] In order to solve the above problems, the present invention provides an intestinal flow field modeling method and device based on bidirectional fluid-solid coupling, which takes into account the bidirectional interaction between the solid domain of the intestinal wall and the fluid domain of the intestinal contents, and realizes more accurate intestinal flow field simulation.

[0005] The technical solution adopted by the present invention is:

[0006] In a first aspect, the present application discloses an intestinal flow field modeling method based on bidirectional fluid-solid coupling, comprising:

[0007] S1. Collecting intestinal multimodal data; wherein the multimodal data includes geometric parameters, movement characteristics, content statistics and wall stress and strain data of the intestine;

[0008] S2, 3D reconstruction of the real human intestinal geometry model;

[0009] S3, preprocessing the established intestinal geometric model by format conversion and simplification modification;

[0010] S4, dividing the preprocessed model into a fluid domain and a solid domain, and establishing a bidirectional fluid-solid coupling model framework;

[0011] S5. Perform fluid domain simulation settings: simulate multiphase flow contents and set the fluid simulation model;

[0012] S6. Perform solid domain simulation settings: set intestinal wall material parameters to simulate intestinal movement;

[0013] S7. Realize bidirectional fluid-solid coupling and simulate the intestinal flow field.

[0014] As an optional technical solution, the geometric parameters include the length, shape and wall thickness of the intestine, the movement characteristics include the type, frequency and rhythm of intestinal movement, and the content statistics include the main types, distribution characteristics and proportion information of intestinal contents.

[0015] As an optional technical solution, the intestinal geometric model in step S2 is directly obtained from an open source database of digital phantoms.

[0016] As an optional technical solution, the preprocessing in step S3 includes:

[0017] S31. Perform model format conversion: convert the model from OBJ format to a solid structure format compatible with Ansys Workbench software;

[0018] S32, perform model simplification processing: reduce the complexity of the intestinal model through smoothing and shrinking geometric operations;

[0019] S33. Perform model modification processing: accurately cut the inlet and outlet of the intestinal segment by setting the splitting surface to set the boundary conditions required for simulation analysis.

[0020] As an optional technical solution, the step S4 of dividing the model fluid domain and solid domain and establishing a bidirectional fluid-solid coupling model framework includes:

[0021] S41. Divide the model fluid domain and solid domain by using shell extraction or Boolean operation substract in the Design Modeler module of Ansys Workbench software;

[0022] S42. A bidirectional fluid-solid coupling model architecture was established in Ansys Workbench software: the fluid domain was processed in the Fluent module, the solid domain was processed in the Transient Structual module, and the two modules were connected through the System Coupling module for bidirectional data transmission.

[0023] As an optional technical solution, the simulation setting of the fluid domain in step S5 includes:

[0024] S51. Suppress the solid domain, name and set the inlet, outlet, and fluid-solid coupling interface of the fluid domain, and perform meshing;

[0025] S52. Define the material properties of multiphase flow contents: the gas phase usually uses the software air model, and the liquid and solid phases customize the material density and viscosity information according to the model settings and application scenarios;

[0026] S53, defining a fluid simulation model: including the definition of a turbulence model and a multiphase flow model, selecting a primary phase and a secondary phase, and setting model parameters;

[0027] S54, set initial conditions and boundary conditions: define the inlet condition as velocity inlet and the outlet condition as pressure outlet;

[0028] S55. Set a dynamic grid and define the dynamic grid method of the fluid-solid coupling interface as system coupling to achieve the subsequent transfer of fluid-solid coupling data from the fluid domain to the solid domain.

[0029] As an optional technical solution, the solid domain simulation setting in step S6 includes:

[0030] S61. Define intestinal wall material properties: set the intestinal material type to linear elasticity, viscoelasticity or hyperelasticity, import experimental data to fit material parameters or directly set material parameter values, wherein the material parameter values ​​include Young's modulus and Poisson's ratio;

[0031] S62, suppress the fluid domain, name the fluid-solid coupling interface for the solid domain, set the target thickness for the solid domain to simulate the real intestinal wall, and perform meshing;

[0032] S63, setting displacement boundary conditions to simulate the segmented contraction movement of the intestine;

[0033] S64. Set up simple support to restrict intestinal movement and deformation;

[0034] S65. Set a fluid-solid coupling interface to achieve the subsequent transfer of fluid-solid coupling data from the solid domain to the fluid domain.

[0035] In a second aspect, the present application also discloses an intestinal flow field modeling device based on bidirectional fluid-solid coupling, comprising:

[0036] An acquisition module, used to collect intestinal multimodal data; wherein the multimodal data includes geometric parameters, movement characteristics, content statistics and wall stress and strain data of the intestine;

[0037] 3D reconstruction module, used to reconstruct the real human intestinal geometry model in 3D;

[0038] A preprocessing module is used to perform format conversion and simplified modification on the established intestinal geometric model;

[0039] The fluid-solid partitioning module is used to partition the preprocessed model into the fluid domain and the solid domain, and establish a bidirectional fluid-solid coupling model architecture;

[0040] The fluid domain setting module is used to perform fluid domain simulation settings to simulate multiphase flow contents and set the fluid simulation model;

[0041] Solid domain setting module, used for solid domain simulation setting, setting intestinal wall material parameters, and simulating intestinal movement;

[0042] The flow field simulation module is used to realize bidirectional fluid-solid coupling and simulate the intestinal flow field.

[0043] In a third aspect, the present application also discloses an electronic device, comprising: one or more processors; one or more memories; the one or more memories storing one or more computer programs, the one or more computer programs comprising instructions, which, when executed by the one or more processors, enable the electronic device to perform the method described in the first aspect above.

[0044] In a fourth aspect, the present application further discloses a computer-readable medium, comprising a computer program, which, when executed on a computer, enables the computer to execute the method described in the first aspect above.

[0045] The beneficial effects of the present invention are:

[0046] 1. Establish bidirectional fluid-solid coupling between the intestinal content flow domain and the intestinal wall solid domain to achieve a more realistic intestinal flow field digital simulation effect.

[0047] 2. By adjusting the model parameters, the flow field state of different intestinal segments at different time periods can be simulated. This has important research significance for analyzing the intrinsic relationship between intestinal motility, intestinal content state and intestinal flow field, and lays the foundation for subsequent analysis of intestinal function. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] Figure 1 It is a flow chart of the intestinal flow field modeling method based on bidirectional fluid-solid coupling in the embodiment.

[0049] Figure 2 Schematic diagram of the three-dimensionally reconstructed intestinal geometric model in the embodiment.

[0050] Figure 3 Schematic diagram of the model modification process in the embodiment.

[0051] Figure 4 is a schematic diagram of the solid domains divided in the examples.

[0052] Figure 5 Schematic diagram of the fluid domains divided in the embodiment.

[0053] Figure 6Schematic diagram of data transmission of the bidirectional fluid-solid coupling model architecture established in the embodiment.

[0054] Figure 7 It is a schematic diagram of the fluid domain meshing results.

[0055] Figure 8 Schematic diagram of the gas volume fraction after initialization in the embodiment.

[0056] Fig. 9 Schematic diagram of the solid domain meshing result in the embodiment.

[0057] Fig.10 It is a simulation effect diagram of the simulated intestinal segmental contraction movement in the embodiment.

[0058] Fig.11 It is a schematic diagram of the model after simple support is set in the embodiment.

[0059] Fig.12 Schematic diagram of the interface of two-phase fluid in the embodiment.

[0060] Fig.13 3 is the velocity vector diagram of the fluid-solid interface in the embodiment.

[0061] Fig.14 This is a schematic diagram of the intestinal flow field modeling device based on bidirectional fluid-solid coupling. DETAILED DESCRIPTION

[0062] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. The steps and modules of the embodiments of the present invention generally described and shown in the drawings here can be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present invention provided in the drawings is not intended to limit the scope of the claimed invention, but merely represents selected embodiments of the present invention. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0063] Example

[0064] like Figure 1 As shown, the present application discloses an intestinal flow field modeling method based on bidirectional fluid-solid coupling, including:

[0065] S1. Collect intestinal multimodal data; wherein the multimodal data includes geometric parameters, movement characteristics, content statistics and wall stress and strain data of the intestine, which provides important support for the subsequent establishment of a three-dimensional geometric model of the intestine, the realization of segmented intestinal movement, the determination of the constitutive model of the intestinal wall material, the construction of a content flow model and other key steps;

[0066] S2, 3D reconstruction of the real human intestinal geometry model;

[0067] S3, preprocessing the established intestinal geometric model by format conversion and simplification modification;

[0068] S4, dividing the preprocessed model into a fluid domain and a solid domain, and establishing a bidirectional fluid-solid coupling model framework;

[0069] S5. Perform fluid domain simulation settings: simulate multiphase flow contents and set the fluid simulation model;

[0070] S6. Perform solid domain simulation settings: set intestinal wall material parameters to simulate intestinal movement;

[0071] S7. Realize bidirectional fluid-solid coupling and simulate the intestinal flow field.

[0072] As an optional embodiment, the geometric parameters include the length, shape and wall thickness of the intestine, the movement characteristics include the type, frequency and rhythm of intestinal movement, and the content statistics include the main type, distribution characteristics and proportion information of intestinal contents.

[0073] As an optional implementation, the intestinal geometric model in step S2 is obtained by performing image segmentation and three-dimensional reconstruction on a real intestinal CT image of a human body, or is directly obtained from an open source database of digital phantoms.

[0074] As an optional implementation, the preprocessing in step S3 includes:

[0075] S31. Perform model format conversion: convert the model from OBJ format to a solid structure format compatible with Ansys Workbench software;

[0076] S32, perform model simplification processing: reduce the complexity of the intestinal model through smoothing and shrinking geometric operations;

[0077] S33. Perform model modification processing: accurately cut the inlet and outlet of the intestinal segment by setting the splitting surface to set the boundary conditions required for simulation analysis.

[0078] As an optional implementation, the step S4 of dividing the model fluid domain and solid domain to establish a bidirectional fluid-solid coupling model framework includes:

[0079] S41. In the Design Modeler module of Ansys Workbench software, the model fluid domain (intestinal content fluid) and solid domain (intestinal wall) are divided by shell extraction or Boolean operation substract operation;

[0080] S42. A bidirectional fluid-solid coupling model architecture was established in Ansys Workbench software: the fluid domain was processed in the Fluent module, the solid domain was processed in the Transient Structual module, and the two modules were connected through the System Coupling module for bidirectional data transmission.

[0081] As an optional implementation, the simulation setting of the fluid domain in step S5 includes:

[0082] S51. Suppress the solid domain, name and set the inlet, outlet, and fluid-solid coupling interface of the fluid domain, and perform meshing;

[0083] S52. Define the material properties of multiphase flow contents: the gas phase usually uses the software air model, and the liquid and solid phases customize the material density and viscosity information according to the model settings and application scenarios;

[0084] S53, defining a fluid simulation model: including the definition of a turbulence model and a multiphase flow model, selecting a primary phase and a secondary phase, and setting model parameters;

[0085] S54, set initial conditions and boundary conditions: define the inlet condition as velocity inlet and the outlet condition as pressure outlet;

[0086] S55. Set a dynamic grid and define the dynamic grid method of the fluid-solid coupling interface as system coupling to achieve the subsequent transfer of fluid-solid coupling data from the fluid domain to the solid domain.

[0087] As an optional implementation, the solid domain simulation setting in step S6 includes:

[0088] S61. Define intestinal wall material properties: set the intestinal material type to linear elasticity, viscoelasticity or hyperelasticity, import experimental data to fit material parameters or directly set material parameter values, wherein the material parameter values ​​include Young's modulus and Poisson's ratio;

[0089] S62, suppress the fluid domain, name the fluid-solid coupling interface for the solid domain, set the target thickness for the solid domain to simulate the real intestinal wall, and perform meshing;

[0090] S63, setting displacement boundary conditions to simulate the segmented contraction movement of the intestine;

[0091] S64. Set up simple support to restrict intestinal movement and deformation;

[0092] S65. Set a fluid-solid coupling interface to achieve the subsequent transfer of fluid-solid coupling data from the solid domain to the fluid domain.

[0093] In order to better understand this embodiment, this embodiment is further described below.

[0094] The intestinal flow field modeling method based on bidirectional fluid-solid coupling provided in this embodiment can be roughly divided into the following steps:

[0095] 1. Collect intestinal multimodal data.

[0096] Specifically, the intestine consists of the small intestine, the large intestine, and the rectum. The small intestine is the longest part, with an adult's small intestine length of about 6-7 meters, while the large intestine is about 1.5 meters long. The shape of the intestine is tortuous, which helps to mix and move food during digestion. The thickness of the intestinal wall varies in different parts. The small intestinal wall is composed of the mucosal layer, submucosa, muscular layer, and serosa, and is relatively thin; the large intestinal wall is thicker, especially in the colon area. The main intestinal movement modes include peristalsis, segmental contraction, and swinging contraction. Peristalsis can produce a net propulsion effect along the direction of the intestine, and the other two movement models are mainly used to mix the intestinal contents. Intestinal contents include undigested food residues, water, bacteria, digestive juices, and gases. Their distribution location, proportion, and related characteristics vary due to changes in different segments of the intestine, individual physiological states, and time stages, showing significant dynamic characteristics.

[0097] The multimodal data collected include geometric parameters, motion characteristics, content statistics and wall stress-strain data of the intestine.

[0098] Among them, the intestinal geometric parameters are used to establish a detailed three-dimensional intestinal geometric model, including the precise characterization of the degree of curvature, diameter change and segment length; the motion characteristic data are used to set the segmented peristalsis form in the simulation, and specifically guide the parameterized definition of the contraction cycle, amplitude and propagation rate to improve the biological fit of the simulation model; the content statistics are used to construct the content flow model, which simulates the actual fluid properties by describing the distribution ratio of different components (such as food residues, water, bacteria, etc.); the wall stress and strain data provide support for the definition of the intestinal wall material properties, and are used to determine parameters such as Young's modulus and Poisson's ratio.

[0099] 2. Three-dimensional reconstruction of the real human intestinal geometry model.

[0100] Specifically, Figure 2 As shown, this embodiment uses the colon module of the human body phantom open source database BodyParts3D for analysis.

[0101] 3. Model preprocessing.

[0102] Specifically, it includes intestinal model format conversion and simplified modification. This embodiment completes preprocessing through the SpaceClaim module of Ansys Workbench software, including the following steps:

[0103] (31) Model format conversion: Use the Auto Skin method to achieve the conversion from OBJ file format to CAD solid structure format;

[0104] (32) Model simplification: Simplify the intestinal geometry model through smoothing and shrinking geometric operations;

[0105] (33) Model modification: The inlet and outlet of the intestinal segment are precisely cut by setting the split surface to set the boundary conditions required for simulation analysis. Figure 3 As shown in the figure, inlet is the entrance and outlet is the exit.

[0106] 4. Divide the model into fluid domain and solid domain, and establish a bidirectional fluid-solid coupling model framework, including:

[0107] (41) The preprocessed model is imported into the Design Modeler module, and the solid domain (intestinal wall) is divided by the substract operation of the Boolean operation after shell extraction, as shown in Figure 4 As shown, the remaining part is preserved as the fluid domain (intestinal content fluid), such as Figure 5 shown.

[0108] (42) Figure 6 As shown in the figure, the Fluent module and the TransientStructual module are connected through the System Coupling module to perform bidirectional data transmission between the fluid domain and the solid domain.

[0109] 5. Fluid domain simulation settings: simulate multiphase flow content and set the fluid simulation model. In this embodiment, this step is completed by the Fluent module of Ansys Workbench software.

[0110] Specifically, the steps include:

[0111] (51) Import the model processed in step (41) into the Meshing module, suppress the solid domain, select the surface of the fluid domain to name the inlet, outlet, and fluid-solid coupling interface, select the tetrahedron method for meshing, and use Fluent as the solver. The final number of mesh units is 691442, and the mesh unit quality reaches 0.83415. The meshing results of the fluid domain are as follows: Figure 7 shown.

[0112] (52) Define the material properties of multiphase flow contents: In this embodiment, the simulated intestinal contents are set as incompressible gas-liquid two-phase flow, so the gas phase model is selected as the air model in the module material library, and the material parameters are: density is 1.225 kg / m 3 , the viscosity is 1.7894×10 -5 kg / (m·s), liquid phase selects custom material density and viscosity, density is 1000kg / m 3 , the viscosity is 0.005kg / (m·s).

[0113] (53) Define the fluid simulation model: mainly including the definition of turbulence model and multiphase flow model. This embodiment aims to simulate the colon flow field for a period of time after a meal, so the corresponding flow field model is: the chyme enters the colon cavity filled with air and containing a certain volume of chyme under the push of peristalsis. In combination with the content flow mentioned in step (52) as an incompressible fluid, the multiphase flow model uses the VOF model, with 2 phases, in which the main phase is set to the gas phase, the secondary phase is set to the liquid phase, the two-phase interaction is set to the surface tension model, and the surface tension coefficient is set to 0.075; due to the low velocity of the intestinal contents, the Reynolds number of the content flow is low, so the turbulence model is selected as the RNG k-ε turbulence model.

[0114] (54) Set initial conditions and boundary conditions: According to the flow field model of this embodiment mentioned in step (53), define the inlet condition as a velocity inlet, the inlet enters a liquid phase with a volume fraction of 1, and the velocity is 0.015 m / s, simulating the chyme entering the colon under the action of peristalsis; the outlet condition is a pressure outlet, and the outlet pressure is 0 Pa; set a unit marking area, and the area is initialized to a liquid phase with a volume fraction of 1 to simulate the retained chyme at the bottom of the colon before the inlet chyme enters, and the remaining area is initialized to a gas phase with a volume fraction of 1. After initialization, the gas volume fraction is as follows: Figure 8 shown.

[0115] (55) Set dynamic mesh: Define the dynamic mesh method of the fluid-solid coupling interface as system coupling, which is achieved through smoothing and re-meshing. Smoothing refers to a technical method that optimizes the position of mesh nodes during mesh deformation to make mesh deformation smoother, avoid inappropriate mesh distortion, and maintain mesh quality and geometric structure stability.

[0116] 6. Solid domain simulation settings: Set intestinal wall material parameters to simulate intestinal movement. This step is completed by the Transient Structual module of AnsysWorkbench software in this embodiment. Specifically, the following steps are included:

[0117] (61) Define the intestinal wall material properties: In this embodiment, the intestinal material is set as a linear elastic material, and the intestinal wall simulation material is defined by directly setting the material elastic modulus to 10 MPa, the Poisson's ratio to 0.48, and the material density to 2000 kg / m3.

[0118] (62) Import the model processed in step (41), suppress the fluid domain, and name the solid domain for the fluid-solid coupling interface. To simulate the real intestinal wall effect, set the solid domain, i.e. the intestinal wall thickness, to 0.01 m, and select the simulation material set in step (61) in the engineering material. Use the triangle method for meshing, the solver is NotlinearMachanical, and the final mesh unit number is 4465, the unit quality is 0.96148, and the solid domain meshing results are as follows: Fig. 9 shown.

[0119] (63) Set displacement boundary conditions to simulate the segmented contraction movement of the intestine. According to step (53), this embodiment simulates the flow field and sound field in the colon for a period of time after a meal. For a period of time after a meal, the segmented contraction is active, which can achieve full mixing of the contents and make a great contribution to the generation of bowel sounds. Therefore, this embodiment simulates segmented contraction with a contraction period of 4s, the contraction wavelength is set to 0.07m, and the contraction amplitude is 0.001m. This is achieved in the Transient Mechanical module by applying displacement boundary condition constraints on the wall. The specific simulation effect is as follows: Fig.10 As shown in the figure, Notlinear Mechanical and Transient Mechanical modules are the corresponding functional modules of Ansys software.

[0120] (64) Set up simple supports to prevent excessive deformation. Fig.11 The simple support constraints shown in the figure act on the appropriate areas of the colon entrance, colon exit, transition between ascending colon and transverse colon, and transition between transverse colon and descending colon, respectively, allowing the selected area to rotate but not to move. The support of physiological structures such as intestinal ligaments on the intestine is simulated to avoid excessive distortion and deformation of the intestinal wall during simulated movement.

[0121] (65) Set up a fluid-solid coupling interface to achieve two-way data transmission.

[0122] 7. Realize bidirectional fluid-solid coupling and simulate intestinal flow field.

[0123] Specifically, the fluid domain transmits the pressure data to the solid domain, and the solid domain transmits the interface node displacement information to the fluid domain. The end time is set to 4s, the time step is 0.0005s, the minimum number of iterations is 1, and the maximum number of iterations is 5. Thus, a bidirectional fluid-solid coupling simulation is realized, and the intestinal flow field simulation results are obtained, as shown in Figure 2. Fig.12 , Fig.13 As shown, the velocity vector diagrams of the two-phase fluid interface and the fluid-solid interface are shown respectively.

[0124] In another embodiment, Fig.14 As shown, an intestinal flow field modeling device based on bidirectional fluid-solid coupling is also disclosed, including:

[0125] An acquisition module, used to collect intestinal multimodal data; wherein the multimodal data includes geometric parameters, movement characteristics, content statistics and wall stress and strain data of the intestine;

[0126] 3D reconstruction module, used to reconstruct the real human intestinal geometry model in 3D;

[0127] A preprocessing module is used to perform format conversion and simplified modification on the established intestinal geometric model;

[0128] The fluid-solid partitioning module is used to partition the preprocessed model into the fluid domain and the solid domain, and establish a bidirectional fluid-solid coupling model architecture;

[0129] The fluid domain setting module is used to perform fluid domain simulation settings to simulate multiphase flow contents and set the fluid simulation model;

[0130] Solid domain setting module, used for solid domain simulation setting, setting intestinal wall material parameters, and simulating intestinal movement;

[0131] The flow field simulation module is used to realize bidirectional fluid-solid coupling and simulate the intestinal flow field.

[0132] In another embodiment, the present application also discloses an electronic device, comprising: one or more processors; one or more memories; the one or more memories storing one or more computer programs, the one or more computer programs comprising instructions, which, when executed by the one or more processors, enable the electronic device to perform the method as in the above embodiment.

[0133] In another embodiment, the present application further discloses a computer-readable medium, including a computer program. When the computer program is executed on a computer, the computer is enabled to execute the method in the above embodiment.

[0134] Those skilled in the art can clearly understand that, for the convenience and brevity of description, the specific working processes of the above-described devices, electronic devices, and computer-readable media can refer to the corresponding processes in the aforementioned method embodiments and will not be repeated here.

[0135] The above description is only a specific implementation mode of the present application, but the protection scope of the present application is not limited thereto. Any technician familiar with the technical field can easily think of changes or substitutions within the technical scope disclosed in the present application, which should be included in the protection scope of the present application. All technical solutions that fall within the scope defined by the claims of the present invention fall within the protection scope of the present invention.

Claims

1. The intestinal flow field modeling method based on bidirectional fluid-solid coupling is characterized by: include: S1. Collecting intestinal multimodal data; wherein the multimodal data includes geometric parameters, movement characteristics, content statistics and wall stress and strain data of the intestine; S2, 3D reconstruction of the real human intestinal geometry model; S3, preprocessing the established intestinal geometric model by format conversion and simplification modification; S4, dividing the preprocessed model into a fluid domain and a solid domain, and establishing a bidirectional fluid-solid coupling model framework; S5. Perform fluid domain simulation settings: simulate multiphase flow contents and set the fluid simulation model; S6. Perform solid domain simulation settings: set intestinal wall material parameters to simulate intestinal movement; S7. Realize bidirectional fluid-solid coupling and simulate the intestinal flow field.

2. The intestinal flow field modeling method based on bidirectional fluid-solid coupling according to claim 1 is characterized in that: The geometric parameters include the length, shape and wall thickness of the intestine, the movement characteristics include the type, frequency and rhythm of intestinal movement, and the content statistics include the main types, distribution characteristics and proportion information of intestinal contents.

3. The intestinal flow field modeling method based on bidirectional fluid-solid coupling according to claim 1 is characterized in that: The intestinal geometric model described in step S2 is directly obtained from the digital phantom open source database.

4. The intestinal flow field modeling method based on bidirectional fluid-solid coupling according to claim 1 is characterized in that: The pre-processing in step S3 includes: S31. Perform model format conversion: convert the model from OBJ format to a solid structure format compatible with Ansys Workbench software; S32, perform model simplification processing: reduce the complexity of the intestinal model through smoothing and shrinking geometric operations; S33. Perform model modification processing: accurately cut the inlet and outlet of the intestinal segment by setting the splitting surface to set the boundary conditions required for simulation analysis.

5. The intestinal flow field modeling method based on bidirectional fluid-solid coupling according to claim 1 is characterized in that: The step S4 of dividing the model fluid domain and solid domain and establishing a bidirectional fluid-solid coupling model framework includes: S41. Divide the model fluid domain and solid domain by using shell extraction or Boolean operation substract in the Design Modeler module of Ansys Workbench software; S42. A bidirectional fluid-solid coupling model architecture was established in Ansys Workbench software: the fluid domain was processed in the Fluent module, the solid domain was processed in the Transient Structual module, and the two modules were connected through the System Coupling module for bidirectional data transmission.

6. The intestinal flow field modeling method based on bidirectional fluid-solid coupling according to claim 2 is characterized in that: The simulation setting of the fluid domain in step S5 includes: S51. Suppress the solid domain, name and set the inlet, outlet, and fluid-solid coupling interface of the fluid domain, and perform meshing; S52. Define the material properties of multiphase flow contents: the gas phase usually uses the software air model, and the liquid and solid phases customize the material density and viscosity information according to the model settings and application scenarios; S53, defining a fluid simulation model: including the definition of a turbulence model and a multiphase flow model, selecting a primary phase and a secondary phase, and setting model parameters; S54, set initial conditions and boundary conditions: define the inlet condition as velocity inlet and the outlet condition as pressure outlet; S55. Set a dynamic grid and define the dynamic grid method of the fluid-solid coupling interface as system coupling to achieve the subsequent transfer of fluid-solid coupling data from the fluid domain to the solid domain.

7. The intestinal flow field modeling method based on bidirectional fluid-solid coupling according to claim 1 is characterized in that: The solid domain simulation setting in step S6 includes: S61. Define intestinal wall material properties: set the intestinal material type to linear elasticity, viscoelasticity or hyperelasticity, import experimental data to fit material parameters or directly set material parameter values, wherein the material parameter values ​​include Young's modulus and Poisson's ratio; S62, suppress the fluid domain, name the fluid-solid coupling interface for the solid domain, set the target thickness for the solid domain to simulate the real intestinal wall, and perform meshing; S63, setting displacement boundary conditions to simulate the segmented contraction movement of the intestine; S64. Set up simple support to restrict intestinal movement and deformation; S65. Set a fluid-solid coupling interface to achieve the subsequent transfer of fluid-solid coupling data from the solid domain to the fluid domain.

8. The intestinal flow field modeling device based on bidirectional fluid-solid coupling is characterized by: include: An acquisition module, used to collect intestinal multimodal data; wherein the multimodal data includes geometric parameters, movement characteristics, content statistics and wall stress and strain data of the intestine; 3D reconstruction module, used to reconstruct the real human intestinal geometry model in 3D; A preprocessing module is used to perform format conversion and simplified modification on the established intestinal geometric model; The fluid-solid partitioning module is used to partition the preprocessed model into the fluid domain and the solid domain, and establish a bidirectional fluid-solid coupling model architecture; The fluid domain setting module is used to perform fluid domain simulation settings to simulate multiphase flow contents and set the fluid simulation model; Solid domain setting module, used for solid domain simulation setting, setting intestinal wall material parameters, and simulating intestinal movement; The flow field simulation module is used to realize bidirectional fluid-solid coupling and simulate the intestinal flow field.

9. An electronic device, characterized in that: include: one or more processors; One or more memories; the one or more memories store one or more computer programs, the one or more computer programs include instructions, when the instructions are executed by the one or more processors, the electronic device executes the method as described in any one of claims 1-7.

10. A computer-readable medium, characterized in that The method comprises a computer program, which, when executed on a computer, causes the computer to execute the method according to any one of claims 1 to 7.

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