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

Abstract

The present invention discloses an intestinal flow field modeling method and device based on bidirectional fluid-solid coupling. The method comprises: S1, collecting intestinal multimodal data; wherein the multimodal data includes geometric parameters, motion characteristics, content statistics and wall stress and strain data of the intestine; S2, reconstructing a three-dimensional geometric model of the human intestine; S3, preprocessing the established intestinal geometric model by format conversion and simplification and modification; S4, dividing the preprocessed model into a fluid domain and a solid domain, and establishing a bidirectional fluid-solid coupling model architecture; S5, performing fluid domain simulation settings: simulating multiphase flow contents and setting a fluid simulation model; S6, performing solid domain simulation settings: setting intestinal wall material parameters and simulating intestinal movement; S7, achieving bidirectional fluid-solid coupling and simulating the intestinal flow field. The method takes into account the bidirectional interaction between the intestinal wall solid domain and the intestinal content fluid domain, achieving more accurate intestinal flow field simulation.

Description

Technical Field

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

[0002] Gastrointestinal disorders are among the most common diseases worldwide. An international multicenter study found that over 40% of the global population suffers from functional gastrointestinal disorders. Therefore, understanding the physiological state of the intestine is crucial for reducing the burden of related diseases. However, intestinal physiology is complex and variable, with significant variations in intestinal flow patterns across different segments and at different times.

[0003] Numerical simulation, as a method of simulating complex medical phenomena using computer algorithms, is commonly 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 achieves more accurate intestinal flow field simulation.

[0005] The technical solution adopted in 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 intestinal geometric parameters, movement characteristics, content statistics, and wall stress and strain data;

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

[0009] S3. Preprocessing of format conversion and simplified modification of the established intestinal geometric model;

[0010] S4. Divide the preprocessed model into a fluid domain and a solid domain, and establish a bidirectional fluid-solid coupling model architecture;

[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 type, 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: 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 split 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 to establish a bidirectional fluid-solid coupling model architecture includes:

[0021] S41. In the Design Modeler module of Ansys Workbench software, use the substract operation of shell extraction or Boolean operation to divide the model fluid domain and solid domain;

[0022] S42. A bidirectional fluid-structure coupling model architecture was established in Ansys Workbench software: the fluid domain was processed in the Fluent module, and the solid domain was processed in the Transient Structual module. 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 use customized material density and viscosity information based on the model settings and application scenarios;

[0026] S53. Define the fluid simulation model: including the definition of turbulence model and multiphase flow model, select the primary phase and secondary phase, and set the 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 the dynamic mesh and define the dynamic mesh 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, including 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 supports to constrain 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 is 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;

[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 divide the pre-processed 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 settings, 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 execute 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 3 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-dimensional reconstructed intestinal geometric model in the embodiment.

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

[0051] Figure 4 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-structure 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] Figure 9 Schematic diagram of the solid domain meshing result in the embodiment.

[0057] Figure 10 3 is a simulation effect diagram of the simulated intestinal segmental contraction movement in the embodiment.

[0058] Figure 11 Schematic diagram of the model after simple support is set in the embodiment.

[0059] Figure 12 Schematic diagram of the interface of two-phase fluids in the embodiment.

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

[0061] Figure 14 This is a structural 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 herein 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 invention claimed for protection, but merely represents selected embodiments of the present invention. Based on the embodiments of 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 multimodal intestinal data; wherein, the multimodal data includes intestinal geometric parameters, movement characteristics, content statistics, and wall stress and strain data, providing important support for subsequent key steps such as establishing a three-dimensional intestinal geometric model, realizing segmented intestinal movement, determining the constitutive model of the intestinal wall material, and constructing a content flow model;

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

[0067] S3. Preprocessing of format conversion and simplified modification of the established intestinal geometric model;

[0068] S4. Divide the preprocessed model into a fluid domain and a solid domain, and establish a bidirectional fluid-solid coupling model architecture;

[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 human intestinal CT image, 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: 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 split 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 architecture includes:

[0079] S41. In the Design Modeler module of Ansys Workbench software, use shell extraction or Boolean substract operations to divide the model into the fluid domain (intestinal content fluid) and the solid domain (intestinal wall);

[0080] S42. A bidirectional fluid-structure coupling model architecture was established in Ansys Workbench software: the fluid domain was processed in the Fluent module, and the solid domain was processed in the Transient Structual module. 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 use customized material density and viscosity information based on the model settings and application scenarios;

[0084] S53. Define the fluid simulation model: including the definition of turbulence model and multiphase flow model, select the primary phase and secondary phase, and set the 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 the dynamic mesh and define the dynamic mesh 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, including 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 supports to constrain 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-structure coupling provided in this embodiment can be roughly divided into the following steps:

[0095] 1. Collect multimodal intestinal data.

[0096] Specifically, the intestine consists of the small intestine, large intestine and 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 the digestion process. The thickness of the intestinal wall varies in different parts. The small intestinal wall is composed of the mucosal layer, submucosa, muscular layer and serosal layer, 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, while the other two movement modes 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 with changes in different segments of the intestine, individual physiological state and time stage, showing significant dynamic characteristics.

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

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

[0099] 2. 3D reconstruction of the real human intestinal geometry model.

[0100] Specifically, if 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 uses the SpaceClaim module of Ansys Workbench software to complete the preprocessing, 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 and solid domains and establish a bidirectional fluid-solid coupling model architecture, including:

[0107] (41) Import the preprocessed model into the Design Modeler module, extract the shell, and use the substract operation of the Boolean operation to divide the solid domain (intestinal wall), as shown in the following example: Figure 4 As shown in , the remaining part is preserved as the fluid domain (intestinal content fluid), as Figure 5 shown.

[0108] (42) Figure 6 As shown in Figure 1, 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 contents and set up the fluid simulation model. In this embodiment, this step is completed using the Fluent module of Ansys Workbench software.

[0110] Specifically, the method includes the following steps:

[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 to be 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 peristaltic push. Combined with the fact that the content flow mentioned in step (52) is an incompressible fluid, the multiphase flow model uses the VOF model, with two phases, in which the main phase is set as the gas phase and the secondary phase is set as the liquid phase. The two-phase interaction is set as the surface tension model, and the surface tension coefficient is set as 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 velocity inlet, the inlet enters the liquid phase with a volume fraction of 1, and the velocity is 0.015m / s, simulating the chyme entering the colon under the action of peristalsis; the outlet condition is pressure outlet, and the outlet pressure is 0Pa; set the unit mark area, and initialize the area to the 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 rest of the area is initialized to the gas phase with a volume fraction of 1. After initialization, the gas volume fraction is as follows: Figure 8 shown.

[0115] (55) Dynamic mesh setting: The dynamic mesh method of the fluid-structure coupling interface is defined 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 the mesh deformation smoother, avoid inappropriate mesh distortion, and maintain mesh quality and geometric structure stability.

[0116] 6. Solid domain simulation settings: Set the intestinal wall material parameters to simulate intestinal movement. This step is completed in this embodiment using the Transient Structual module of Ansys Workbench software. Specifically, it includes the following steps:

[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 as the fluid-solid coupling interface. To simulate the real intestinal wall effect, set the solid domain, i.e. the intestinal wall thickness, to 0.01m, 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: Figure 9 shown.

[0119] (63) Set displacement boundary conditions to simulate the segmental 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 segmental contraction is active, which can achieve full mixing of the contents and make a huge contribution to the generation of bowel sounds. Therefore, this embodiment simulates segmental contraction with a contraction period of 4s, a contraction wavelength of 0.07m, and a contraction amplitude of 0.001m. In the Transient Mechanical module, displacement boundary condition constraints are imposed on the wall to achieve this. The specific simulation effect is as follows: Figure 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. Figure 11 The simple support constraints shown here apply to appropriate regions of the colon, including the inlet and outlet, the transition between the ascending and transverse colons, and the transition between the transverse and descending colons. These constraints allow rotation but not movement in the selected regions. This simulates the support provided by physiological structures such as the ligament to the intestine, preventing excessive distortion and deformation of the intestinal wall during simulated motion.

[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 pressure data to the solid domain, and the solid domain transmits 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. This realizes the bidirectional fluid-solid coupling simulation and obtains the intestinal flow field simulation results, as shown in Figure 2. Figure 12 、 Figure 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, Figure 14 As shown, an intestinal flow field modeling device based on bidirectional fluid-solid coupling is also disclosed, including:

[0125] An acquisition module is 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;

[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 divide the pre-processed 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 settings, 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 execute 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 run on a computer, the computer is caused to execute the method in the above embodiment.

[0134] Those skilled in the art will 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 is only a specific implementation method of the present application, but the scope of protection of the present application is not limited thereto. Any technician familiar with the technical field can easily think of changes or replacements within the technical scope disclosed in the present application, which should be included in the scope of protection of the present application. Any technical solution that falls within the scope defined by the claims of the present invention falls within the scope of protection of the present invention.

Claims

1. The intestinal flow field modeling method based on bidirectional fluid-solid coupling is characterized by: include: S1. Collect intestinal multimodal data; wherein the multimodal data includes intestinal geometric parameters, motion characteristics, content statistics, and wall stress and strain data; the geometric parameters include intestinal length, shape, and wall thickness; the motion characteristics include the type, frequency, and rhythm of intestinal motion; and the content statistics include the main types, distribution characteristics, and proportion information of intestinal contents; S2, 3D reconstruction of the real human intestinal geometry model; S3. Preprocessing of format conversion and simplified modification of the established intestinal geometric model; S4. Divide the preprocessed model into a fluid domain and a solid domain, and establish a bidirectional fluid-solid coupling model architecture; 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 intestinal flow field; The simulation settings of the fluid domain in step S5 include: 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 uses the software air model, and the liquid and solid phases use customized material density and viscosity information based on the model settings and application scenarios; S53. Define the fluid simulation model: including the definition of turbulence model and multiphase flow model, select the primary phase and secondary phase, and set the 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 the dynamic mesh and define the dynamic mesh 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; 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, including 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 supports to constrain 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.

2. 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.

3. 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: 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 split surface to set the boundary conditions required for simulation analysis.

4. 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 into fluid domain and solid domain and establishing a bidirectional fluid-solid coupling model architecture includes: S41. In the Design Modeler module of Ansys Workbench software, use the substract operation of shell extraction or Boolean operation to divide the model fluid domain and solid domain; S42. A bidirectional fluid-structure coupling model architecture was established in Ansys Workbench software: the fluid domain was processed in the Fluent module, and the solid domain was processed in the Transient Structual module. The two modules were connected through the System Coupling module for bidirectional data transmission.

5. An intestinal flow field modeling device based on bidirectional fluid-solid coupling, used to implement the method according to any one of claims 1 to 4, characterized in that: The device comprises: An acquisition module is 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; 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 divide the pre-processed 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 settings, 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.

6. 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 including instructions, which, when executed by the one or more processors, enable the electronic device to perform the method according to any one of claims 1 to 4.

7. A computer-readable medium, characterized in that The method comprises a computer program, which, when running on a computer, causes the computer to perform the method according to any one of claims 1 to 4.

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