CN115831373A - Simulation method for polymer esophageal stent implantation - Google Patents
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- 238000000034 method Methods 0.000 title claims abstract description 42
- 238000004088 simulation Methods 0.000 title claims abstract description 24
- 238000002513 implantation Methods 0.000 title claims abstract description 16
- 229920000642 polymer Polymers 0.000 title claims abstract description 16
- 206010028980 Neoplasm Diseases 0.000 claims abstract description 46
- 239000000463 material Substances 0.000 claims abstract description 37
- 210000003238 esophagus Anatomy 0.000 claims abstract description 28
- 238000002591 computed tomography Methods 0.000 claims abstract description 8
- 238000007906 compression Methods 0.000 claims abstract description 7
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- 208000028299 esophageal disease Diseases 0.000 claims description 7
- 230000003902 lesion Effects 0.000 claims description 6
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- 238000004364 calculation method Methods 0.000 claims description 5
- 230000003213 activating effect Effects 0.000 claims description 4
- 238000002940 Newton-Raphson method Methods 0.000 claims description 3
- 239000013013 elastic material Substances 0.000 claims description 3
- 238000012804 iterative process Methods 0.000 claims description 3
- 230000007246 mechanism Effects 0.000 abstract description 2
- 230000005012 migration Effects 0.000 abstract description 2
- 238000013508 migration Methods 0.000 abstract description 2
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- 208000000461 Esophageal Neoplasms Diseases 0.000 description 3
- 206010030155 Oesophageal carcinoma Diseases 0.000 description 3
- 238000013461 design Methods 0.000 description 3
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- 208000007217 Esophageal Stenosis Diseases 0.000 description 1
- 206010030194 Oesophageal stenosis Diseases 0.000 description 1
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Abstract
The application provides a simulation method for polymer esophageal stent implantation, which comprises the following steps of 1) extracting an esophageal model from a CT scanning image of a patient, and then dividing the esophageal model into a tumor model and an esophageal wall model; 2) Converting the tumor model and the esophageal wall model into finite element models; 3) Assigning material parameters of the tumor and esophageal wall in the finite element model; 4) Arranging a press-holding shell, and then assembling the esophageal stent model and the press-holding shell; 5) Pressing the assembled esophageal stent model and the pressing and holding shell into the esophageal model until a preset position is reached; 6) Removing the contact relation between the pressure-holding shell and the esophageal stent model, and removing the compression state of the esophageal stent model, so that the esophageal stent model is self-expanded to be in contact with the esophageal model and reaches mechanical balance; the interaction between the esophageal stent and the esophagus is represented through simulation so as to clarify the migration mechanism of the esophageal stent, and the esophageal stent which is more in line with the structure of a human body is designed so as to provide theoretical basis and guidance for clinical treatment.
Description
Technical Field
The invention belongs to the technical field of simulation of medical instruments, and particularly relates to a simulation method for polymer esophageal stent implantation.
Background
Esophageal cancer is the sixth most common cancer in the world, the morbidity and mortality are high worldwide, and patients with esophageal cancer at the late stage can rarely be cured. Currently, esophageal stents are generally used clinically for palliative treatment. The esophageal stent can relieve the symptoms of benign esophageal stenosis and dysphagia, and can open the blocked esophagus for eating in the late stage of patients with esophageal cancer. However, for esophageal stent placement surgery, the size of the esophageal stent is related to the post-operative health of the patient. If the radial force of the esophageal stent is small, the esophagus cannot be propped open, and the problems of displacement, restenosis and the like are easy to occur, so that the treatment effect is influenced. If the supporting force of the esophageal stent is too large, the pressure of the tube wall is too large, and complications such as bleeding and the like are caused.
With the development of computer and finite element analysis software, finite element analysis has been widely applied to clinical medicine, which saves a lot of time and economic cost, and can be free from the limitation of factors such as field in space, and the obtained result is very close to the real experimental result. The efficiency of scientific research is greatly improved by using finite element analysis technology, and therefore, finite element analysis is increasingly applied to the research of interventional therapy stents, for example: CN 113749833A (Feng Wendong) discloses a finite element analysis method of a vascular stent and the vascular stent, ABAQUS software is used for carrying out stress analysis on a three-dimensional model of the vascular stent, a platelet and a vascular model, a maximum equivalent stress change curve of the vascular stent is obtained according to a stress analysis result, and design of the vascular stent is guided; CN 113974829A (Beijing university of aerospace) discloses a vascular stent implantation simulation method, and the proposed technical scheme simulates the expansion of a vascular stent in a vascular tumor area, provides a vascular stent position and parameters meeting the circulation radius of a vascular wall, and provides technical reference for a doctor before an operation.
At present, simulation analysis about the esophageal stent is not available.
Disclosure of Invention
In view of the above problems in the prior art, the present invention provides a simulation method for polymer esophageal stent implantation.
In order to solve the technical problems, the technical scheme provided by the invention is as follows:
a simulation method for polymer esophageal stent implantation comprises the following steps of:
1) Extracting an esophagus model from a CT scanning image of an esophageal disease patient, and dividing the esophagus model into a tumor model and an esophageal wall model;
2) Converting the tumor model and the esophageal wall model into finite element models;
3) Assigning material parameters of the tumor and material parameters of the esophageal wall in the finite element model;
4) Arranging a pressing and holding shell of the pressing and holding contracted esophageal stent model, wherein the pressing and holding shell is in a thin-wall cylindrical shape, and then assembling the esophageal stent model and the pressing and holding shell;
5) Pressing the assembled esophageal stent model and the pressing and holding shell into the esophageal model until a preset position is reached;
6) And removing the contact relation between the press-holding shell and the esophageal stent model, removing the compression state of the esophageal stent model, and activating the contact relation between the esophageal stent model and the esophageal wall model, so that the esophageal stent model is self-expanded to be in contact with the tumor-carrying esophageal model and reaches mechanical balance.
Preferably, in step 1), the region of the esophagus and the tumor portion in the CT data is separated from other tissues by the segmentation function of the image analysis software, and a real esophageal model is obtained by three-dimensional reconstruction.
Preferably, in the step 2), the tumor model and the esophageal wall model are subjected to meshing by adopting hexahedral meshes.
Preferably, step 3) includes: selecting a nonlinear superelasticity mechanical model from the material models of the tumor and the esophageal wall;
in ABAQUS, the material nonlinearity problem is solved by the Newton-Raphson method;
in nonlinear analysis, an integral balance iteration method is adopted, the load is divided into a plurality of tiny increments and is gradually applied in the calculation process, and the rigidity matrix is adjusted after each increment of the load is finished;
time steps, iterative processes and convergence criteria need to be controlled;
completing balance iteration in each load increment to enable increment solution to reach balance, namely performing iterative solution on the following formula:
K T Δu＝F-F nr ；
in the above formula, K T Is a tangential stiffness matrix;
Δ u is the displacement increment;
f is an external load vector;
F nr is the internal force vector;
the default value is taken to be 0.5% of the average internal force:
||R|| 2 ＜0.005||F|| 2 ；
in the formula: II R II 2 Is the norm of the residual error; II F II 2 Is the norm of force.
Preferably, in the step 3), the material model of the tumor and the esophageal wall is a nonlinear Mooney-Rivlin model, and the material parameters of the superelasticity model are obtained by performing curve fitting on the stress-strain experimental data;
for superelastic materials with nonlinear anisotropy and isotropy, the stress-strain relationship can be derived from the strain-energy density function;
fitting stress-strain tensile data of the material in order to obtain parameters of a superelastic material model;
the parameters of the superelastic material are obtained from an isotropic 5-constant Mooney-Rivlin model;
the strain energy density function is:
wherein
And
for strain invariants, W is a function of strain energy density, c 10 、c 01 、c 11 、c 20 、c 02 And D 1 Is the super elastic constant.
Preferably, in step 4), a squeezing shell is created to realize a squeezing simulation process, and the squeezing shell is only applied to the squeezing process of the esophageal stent model and does not interact with other component models, and the property of the squeezing shell is set as a deformable shell surface.
Preferably, in the step 5), the pressing and holding shell and the esophageal stent model are in surface-to-surface contact, and the universal contact is used as an interaction type;
the friction formula is set as a penalty function, and the friction coefficient is 0.2;
and creating a normal behavior, setting the contact attribute as hard contact, setting the constraint execution method as Standard, and setting the contact rigidity behavior as nonlinear.
Preferably, in the step 5), setting the esophageal stent model and boundary conditions of the esophageal model, including taking one point at the center of one end of the cylindrical surface of the stent as an origin of coordinates, creating a cylindrical coordinate system taking the axis of the cylindrical surface as a Z axis, and taking the direction of a T axis as the radial direction of the stent;
the pressing and holding shell only generates displacement in the T-axis direction, and the displacement in the other directions is set to be 0;
the freedom degrees of one end node of the esophagus model are all restricted except the T axis, so that the esophagus model can only deform in the radial direction after being loaded and cannot rotate around the Z axis.
Preferably, in the step 5), the maximum outer diameter of the esophageal stent model is set to be attached to the pressing and holding shell;
placing the esophageal stent model in a lesion area in the esophageal model;
the esophageal stent model is set to self-expand to cause deformation of the esophageal lesion area.
The application provides a simulation method for polymer esophageal stent implantation, which comprises the following steps in sequence: 1) Extracting an esophagus model from a CT scanning image of an esophageal disease patient, and then dividing the esophagus model into a tumor model and an esophageal wall model; 2) Converting the tumor model and the esophageal wall model into finite element models; 3) Assigning material parameters of the tumor and material parameters of the esophageal wall in the finite element model; 4) Arranging a pressing and holding shell of the pressing and holding contracted esophageal stent model, wherein the pressing and holding shell is in a thin-wall cylindrical shape, and then assembling the esophageal stent model and the pressing and holding shell; 5) Pressing the assembled esophageal stent model and the pressing and holding shell into the esophageal model until a preset position is reached; 6) Removing the contact relation between the press-holding shell and the esophageal stent model, removing the compression state of the esophageal stent model, activating the contact relation between the esophageal stent model and the esophageal wall model, and enabling the esophageal stent model to self-expand to be in contact with the tumor-carrying esophageal model and reach mechanical balance;
the application simulates the biomechanics of the implanted esophageal stent, represents the interaction between the esophageal stent and the esophagus, so as to clarify the migration mechanism of the esophageal stent, design the esophageal stent more conforming to the structure of a human body and provide reference for clinical treatment;
the simulation method provided by the application can provide certain theoretical basis and guidance for the design of the esophageal stent clinical treatment scheme.
Detailed Description
In order to make the objects, 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 with reference to the embodiments of the present invention, and it is obvious that the described embodiments are a part of the embodiments of the present invention, but not all of the embodiments. All other embodiments, which can be obtained by a person skilled in the art without any inventive step based on the embodiments of the present invention, are within the scope of the present invention.
The application provides a simulation method for polymer esophageal stent implantation, which comprises the following steps in sequence:
1) Extracting an esophagus model from a CT scanning image of an esophageal disease patient, and then dividing the esophagus model into a tumor model and an esophageal wall model;
2) Converting the tumor model and the esophageal wall model into a finite element model;
3) Assigning material parameters of the tumor and material parameters of the esophageal wall in the finite element model;
4) Arranging a pressing and holding shell of the pressing and holding contracted esophageal stent model, wherein the pressing and holding shell is in a thin-wall cylindrical shape, and then assembling the esophageal stent model and the pressing and holding shell;
5) Pressing the assembled esophageal stent model and the pressing shell into the esophageal model until a preset position is reached;
6) And removing the contact relation between the press-holding shell and the esophageal stent model, removing the compression state of the esophageal stent model, and activating the contact relation between the esophageal stent model and the esophageal wall model, so that the esophageal stent model is self-expanded to be in contact with the tumor-carrying esophageal model and reaches mechanical balance.
In one embodiment of the present application, in step 1), the region of the esophagus and the tumor portion in the CT data is separated from other tissues by the segmentation function of the image analysis software, and a real esophageal model is obtained by three-dimensional reconstruction.
In one embodiment of the present application, in step 2), the tumor model and the esophageal wall model are gridded using hexahedral mesh.
In one embodiment of the present application, step 3) includes: selecting a nonlinear superelasticity mechanical model for the material models of the tumor and the esophageal wall;
in ABAQUS, the material nonlinearity problem is solved by the Newton-Raphson method;
in the nonlinear analysis, an integral balance iteration method is adopted, the load needs to be divided into a plurality of tiny increments in the calculation process and is gradually applied, and the rigidity matrix is adjusted after each increment of the load is finished;
time steps, iterative processes and convergence criteria need to be controlled;
completing balance iteration in each load increment to enable increment solution to reach balance, namely performing iterative solution on the following formula:
K T Δu＝F-F nr ；
in the above formula, K T Is a tangential stiffness matrix;
Δ u is the displacement increment;
f is an external load vector;
F nr is the internal force vector;
in the iteration process, the result obtained by the calculation of each incremental step is only a result infinitely close to an analytic solution, and an accurate solution cannot be obtained, only when a residual error (unbalance force) F-F nr Within the convergence criterion range, the nonlinear calculation can be converged;
default values are taken to be 0.5% of the average internal force:
||R|| 2 ＜0.005||F || 2 ；
in the formula: II R II 2 Is the norm of the residual error; II F II 2 Is the norm of the force.
In one embodiment of the present application, in step 3), the non-linear Mooney-Rivlin model is selected as the material model of the tumor and esophageal wall, and the material parameters of the superelastic model are obtained by curve fitting of the stress-strain experimental data;
for superelastic materials with nonlinear anisotropy and isotropy, the stress-strain relationship can be derived from the strain-energy density function;
fitting stress-strain elongation data of the material in order to obtain parameters of a superelastic material model;
the parameters of the super-elastic material are obtained by an isotropic 5-constant Mooney-Rivlin model;
the strain energy density function is:
wherein
And
for strain invariants, W is a function of strain energy density, c 10 、c 01 、c 11 、c 20 、c 02 And D 1 Is the super elastic constant.
In one embodiment of the present application, in step 4), a squeezing shell is created to implement a squeezing simulation process, and the squeezing shell is only applied to the squeezing process of the esophageal stent model, and does not interact with other component models, and the property of the squeezing shell is set as a deformable shell surface.
In one embodiment of the application, in the step 5), the pressing and holding shell and the esophageal stent model are arranged to be in surface-to-surface contact, and the common contact is used as an interaction type;
the friction formula is set as a penalty function, and the friction coefficient is 0.2;
and creating a normal behavior, setting the contact attribute as hard contact, setting the constraint execution method as Standard, and setting the contact rigidity behavior as nonlinear.
In an embodiment of the application, in step 5), setting the esophageal stent model and boundary conditions of the esophageal stent model, including taking a point at the center of one end of a cylindrical surface of the stent as an origin of coordinates, creating a cylindrical coordinate system taking the axis of the cylindrical surface as a Z axis, and taking a T axis direction as a radial direction of the stent;
the pressing and holding shell only generates displacement in the T-axis direction, and the displacement in the other directions is set to be 0;
the freedom degrees of one end node of the esophagus model are all restricted except the T axis, so that the esophagus model can only deform in the radial direction after being loaded and cannot rotate around the Z axis.
In one embodiment of the application, in the step 5), the maximum outer diameter of the esophageal stent model is set to be attached to the pressing and holding shell;
placing the esophageal stent model in a lesion area in the esophageal model;
the esophageal stent model is set to self-expand to cause deformation of the esophageal lesion area.
In the present application: the function and function of the press-holding shell are as follows: in reality, the maximum outer diameter of the esophageal stent is larger than the inner diameter of the esophagus, and the esophageal stent is radially tightened to a pressing and holding state by using the conveying catheter, so that the outer diameter of the esophageal stent is reduced to meet the condition of being placed in the esophagus;
in finite element simulation, a pressing and holding shell is created to simulate and serve as a real conveying catheter, the pressing and holding shell is sleeved on an esophageal stent model, the esophageal stent model is sleeved in the pressing and holding shell, external force is generated by the pressing and holding shell to radially press and hold the esophageal stent model, the outer diameter of the esophageal stent model before the esophageal stent model is placed in the esophageal model is smaller than the inner diameter of the esophageal model, the esophageal stent model and the pressing and holding shell are smoothly placed in the esophageal model, then the pressing and holding shell is pulled out, and the esophageal stent model is released and expanded to the original outer diameter after the pressing and holding shell is pulled out.
Methods and devices not described in detail in the present invention are all the prior art and are not described in detail.
For further understanding of the present invention, the following examples are provided to describe the simulation method for esophageal stent implantation in detail, and the scope of the present invention is not limited by the following examples.
Example 1
A simulation method for polymer esophageal stent implantation comprises the following steps of:
1) Extracting an esophagus model from the CT scanning image of the patient with the esophageal disease:
specifically, the step of extracting the esophageal model from the CT scanning image of the esophageal disease patient can be performed by medical image software such as Mimics and the like;
the method for extracting the esophagus model from the CT scanning image of the patient with the esophageal disease comprises the following steps: carrying out threshold segmentation according to the gray level of esophageal tissues in the medical image, carrying out preliminary segmentation on human tissues by using a threshold segmentation tool, carrying out preliminary stripping on the esophageal tissues and other tissues in the image by adjusting the threshold range, and acquiring a preliminary extraction esophageal model;
performing detail repair on the tumor-carrying esophagus model layer by layer in a two-dimensional environment by using 3-Matic software and two-dimensional editing tools, namely Edit Masks and Multiple slice edge, and finally obtaining a primarily separated tumor-carrying esophagus model;
carrying out simple Smoothing treatment on the model by using a Smoothing tool to obtain a relatively smooth tumor-carrying esophagus model;
finally, performing cavitation processing on the model by using a Boolean operation tool;
2) The esophageal model was transformed into a finite element model:
a step of transforming the tumor model and the esophageal wall model into a finite element model, comprising: introducing the model into ABAQUS, selecting 'Seed' from a main menu, and designating the target of the integral unit subdivision size as 1; selecting 'Mesh' and 'Element Type' from a main menu as a component selection unit Type; displaying a dynamics reduction integral eight-node unit C3D8R in a popped up 'Element Type' dialog box to perform meshing on the tumor model and the esophageal wall model, wherein the size of the meshing unit is 1mm;
in addition, for the positions with large curvature and large stress of the tumor model and the esophageal wall model, in order to obtain more accurate results in the simulation process, grid encryption processing is carried out by adopting the grid size of 0.5 mm;
3) Material parameters assigned to the finite element model:
setting material properties of the tumor and esophageal wall in the finite element model, comprising: the material model of the tumor and the esophageal wall is a nonlinear superelasticity model (Mooney-Rivlin model), and the material parameters of the superelasticity model are obtained by performing curve fitting on stress-strain experimental data;
for superelastic materials with nonlinear anisotropy and isotropy, the stress-strain relationship can be derived from the strain-energy density function;
fitting stress-strain tensile data of the material in order to obtain parameters of a superelastic material model;
the parameters of the super-elastic material are obtained by an isotropic 5-constant Mooney-Rivlin model;
its strain energy density function is:
wherein
And
for strain invariants, W is a function of strain energy density, c 10 ，c 01 ，c 11 ，c 20 ，c 02 And D 1 Is the super elastic constant;
the Mooney-Rivlin parameters of the esophageal stent model and the esophageal model are shown in table 1;
TABLE 1 Mooney-Rivlin parameters of esophageal Stent models and esophageal models
4) The pressing and holding shell is arranged to assemble the model:
assembling the esophageal stent model and the pressing shell, so that the centers of circles of the esophageal stent model, the tumor-carrying esophageal model and the pressing shell are located on the same straight line;
5) Compressing an esophageal stent model into an esophageal model, comprising: pressing the esophageal stent model into the esophageal model until a preset position is reached, and in the compression process, pressing the shell to compress the maximum outer diameter of the esophageal stent model to be smaller than the minimum inner diameter of the tumor-carrying esophageal model;
the step of adjusting the position of the esophageal stent model comprises the following steps: setting the maximum outer diameter of the esophageal stent model to be attached to the pressing and holding shell; placing an esophageal stent model in a tumor region in an esophageal model; setting the esophageal stent model to expand to cause deformation of the tumor area;
before the esophageal stent model is pressed into the esophageal model, the maximum outer diameter of the esophageal stent model is larger than the diameter of the tumor area;
6) The esophageal stent model is self-expanded to contact with the esophageal model and reach mechanical balance:
after the esophageal stent model is pressed into the esophageal model until the esophageal stent model reaches a preset position, the contact relation between the pressing and holding shell and the esophageal stent model is removed, the compression state of the esophageal stent model is relieved, the contact relation between the esophageal stent model and the esophageal wall model is activated, and the esophageal stent model is enabled to self-expand to be in contact with the tumor-carrying esophageal model and reach mechanical balance.
The above description of the embodiments is only intended to facilitate the understanding of the method of the invention and its core idea. It should be noted that, for those skilled in the art, it is possible to make various improvements and modifications to the present invention without departing from the principle of the present invention, and those improvements and modifications also fall within the scope of the claims of the present invention.
Claims (9)
1. A simulation method for polymer esophageal stent implantation is characterized by comprising the following steps of:
1) Extracting an esophagus model from a CT scanning image of an esophageal disease patient, and dividing the esophagus model into a tumor model and an esophageal wall model;
2) Converting the tumor model and the esophageal wall model into finite element models;
3) Assigning material parameters of the tumor and material parameters of the esophageal wall in the finite element model;
4) Arranging a pressing and holding shell of the pressing and holding contracted esophageal stent model, wherein the pressing and holding shell is in a thin-wall cylindrical shape, and then assembling the esophageal stent model and the pressing and holding shell;
5) Pressing the assembled esophageal stent model and the pressing and holding shell into the esophageal model until a preset position is reached;
6) And removing the contact relation between the press-holding shell and the esophageal stent model, removing the compression state of the esophageal stent model, and activating the contact relation between the esophageal stent model and the esophageal wall model, so that the esophageal stent model is self-expanded to be in contact with the tumor-carrying esophageal model and reaches mechanical balance.
2. The method for simulating the placement of a polymer esophageal stent according to claim 1, wherein in the step 1), the region of the esophagus and the tumor part in the CT data is separated from other tissues through a segmentation function of image analysis software, and a real esophageal model is obtained through three-dimensional reconstruction.
3. The method for simulating the implantation of a polymer esophageal stent according to claim 1, wherein in the step 2), the tumor model and the esophageal wall model are gridded by adopting hexahedral grids.
4. The method as claimed in claim 1, wherein step 3) comprises: selecting a nonlinear superelasticity mechanical model for the material models of the tumor and the esophageal wall;
in ABAQUS, the material nonlinearity problem is solved by the Newton-Raphson method;
in nonlinear analysis, an integral balance iteration method is adopted, the load is divided into a plurality of tiny increments and is gradually applied in the calculation process, and the rigidity matrix is adjusted after each increment of the load is finished;
time steps, iterative processes and convergence criteria need to be controlled;
completing balance iteration in each load increment to enable increment solution to reach balance, namely performing iterative solution on the following formula:
K T Δu＝F-F nr ；
in the above formula, K T Is a tangential stiffness matrix;
Δ u is the displacement increment;
f is an external load vector;
F nr is the internal force vector;
the default value is taken to be 0.5% of the average internal force:
||R|| 2 ＜0.005||F|| 2 ；
in the formula: II R II 2 Is the norm of the residual error; II F II 2 Is the norm of the force.
5. The method as claimed in claim 1, wherein in step 3), the model of tumor and esophageal wall is a non-linear Mooney-Rivlin model, and the material parameters of the super-elastic model are obtained by curve fitting of stress-strain experimental data;
for superelastic materials with nonlinear anisotropy and isotropy, the stress-strain relationship can be derived from the strain-energy density function;
fitting stress-strain tensile data of the material in order to obtain parameters of a superelastic material model;
the parameters of the super-elastic material are obtained by an isotropic 5-constant Mooney-Rivlin model;
the strain energy density function is:
wherein
And
for strain invariants, W is a function of strain energy density, c 10 、c 01 、c 11 、c 20 、c 02 And D 1 Is the super elastic constant.
6. The simulation method for polymer esophageal stent implantation according to claim 1, wherein in the step 4), a gripping shell is created to realize a gripping simulation process, and the gripping shell is only applied to the gripping process of the esophageal stent model and does not interact with other component models, and the properties of the gripping shell are set as deformable shell surfaces.
7. The simulation method for polymer esophageal stent implantation according to claim 1, wherein in the step 5), the pressing shell and the esophageal stent model are arranged to be in surface-to-surface contact, and the esophageal model and the esophageal stent model are in surface-to-surface contact, and universal contact is used as an interaction type;
the friction formula is set as a penalty function, and the friction coefficient is 0.2;
and creating a normal behavior, setting the contact attribute as hard contact, setting the constraint execution method as Standard, and setting the contact rigidity behavior as nonlinear.
8. The method for simulating the placement of a polymer esophageal stent according to claim 1, wherein in the step 5), the esophageal stent model and boundary conditions of the esophageal stent model are set, and the method comprises the steps of taking a point at the center of one end of a cylindrical surface of the stent as an origin of coordinates, creating a cylindrical coordinate system taking the axis of the cylindrical surface as a Z axis, and taking a T axis direction as a radial direction of the stent;
the pressing and holding shell only generates displacement in the T-axis direction, and the displacement in the other directions is set to be 0;
the freedom degrees of one end node of the esophagus model are all restricted except the T axis, so that the esophagus model is guaranteed to be deformed only in the radial direction after being loaded and cannot rotate around the Z axis.
9. The simulation method for polymer esophageal stent implantation according to claim 1, wherein in the step 5), the maximum outer diameter of the esophageal stent model is set to be attached to the pressing shell;
placing the esophageal stent model in a lesion area in the esophageal model;
the esophageal stent model is set to self-expand to cause deformation of the esophageal lesion area.
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN117030093B (en) * | 2023-08-23 | 2024-01-26 | 杭州糖吉医疗科技有限公司 | Gastric inversion support radial force measuring system for simulated press grasping machine |
| CN117894471A (en) * | 2024-03-15 | 2024-04-16 | 柏意慧心(杭州)网络科技有限公司 | Method, computing device, and medium for simulating the configuration of a stent release contact |
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2022
- 2022-10-28 CN CN202211335377.3A patent/CN115831373A/en active Pending
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN117030093B (en) * | 2023-08-23 | 2024-01-26 | 杭州糖吉医疗科技有限公司 | Gastric inversion support radial force measuring system for simulated press grasping machine |
| CN117894471A (en) * | 2024-03-15 | 2024-04-16 | 柏意慧心(杭州)网络科技有限公司 | Method, computing device, and medium for simulating the configuration of a stent release contact |
| CN117894471B (en) * | 2024-03-15 | 2024-06-07 | 柏意慧心(杭州)网络科技有限公司 | Method, computing device, and medium for simulating the configuration of a stent release contact |
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