Whole ion optics gridlet simulations using a hybridgrid. Stent modeling using immersed finite element method. The new algorithm is based on the threedimensional immersed. Interpolation functions in the immersed boundary and. Several features of this site will not function whilst javascript is disabled. Computational methods in cardiovascular mechanics arxiv. Computational modeling of balloonexpandable stent deployment in coronary artery using the finite element method javascript is currently disabled in your browser. Stent, periodic boundary conditions, finite element method, multiple point constraint. Semiimplicit formulation of the immersed finite element. Computational modeling in order to perform the stent deployment simulation, the fem requires the input of the geometry and the material properties of a the artery, b the plaque, c the stent and d the balloon, as well as, appropriate boundary conditions. A general finite element analysis method for balloon expandable stents based on repeated unit cell ruc model. However, the conventional approach of coupling the fluid and solid domains, as in the immersed boundary method and the immersed finite element method, often cannot handle high reynolds number flows interacting with moving and deformable solids. This work was inspired by the pioneering work of professor t. Benedict verhegghe, expert in finite element and geometrical modeling.
Analysis of the stent expansion in a stenosed artery using. Design van stents met eindige elementen finite element. Finite element methods to analyze helical stent expansion. Modeling stent deployment in realistic arterial segment. In this paper, the finite element method is applied i to understand the effects of different. We have developed a numerical model of the endovascular treatment of abdominal aortic an eurysms aaa using finite element analysis fea, we took into account the geometry of the biological region reconstructed from scans, a local characteriza tion. The immersed finite element method ifem 1922 was developed to tackle this problem by representing the background viscous fluid with an unstructured finite element mesh and nonlinear finite elements for the immersed deformable solid. Finite element analysis of a novel design for a non. The model is firstly validated by experimental work in literature. Multiple wall stents have been use in the therapy of aneurysm 27,28.
Making use of quantitative finite element analyses fea, kumar et al. But only hui mengs team simulated the implantation of braided stent in patientspecific artery models together with in vitro experiments 14, 15, 16 several years ago. Based on lpv, lpc, and smpv model, the radial displacement in the distal region of the stent is larger than the proximal displacement at the second instant shown in figures 4a and 4c. Materials of stent graft nickeltitanium alloys known as nitinol, are alloys where this two elements are present in roughly equal atomic using of finite element method and computational analysis of mechanical properties of stent grafts stepan major, marie hubalovska s. The stents analysed using the finite element method were the s7 medtronic ave and the nir boston scientific stent designs. This method is validated by direct comparison to experimental results from tension tests. Immersed methods for high reynolds number fluidstructure. A balloon is deployed to assist the expansion of the stent which is to be plastically deformed. The goal is to simulate different stages of the endovascular procedure in the preoperative phase. Finite element analysis of mechanical behaviors of multi. However, the radial displacement in the distal region of the stent is closed to the proximal. The introduction of computational models in cardiovascular sciences has been. Aortic endovascular repair modeling using the finite element method article pdf available in journal of biomedical science and engineering 0609.
A group of immersed finite element spaces for elliptic interface problems 14 december 2017 ima journal of numerical analysis, vol. Mathematical foundations of the immersed finite element method. Finite element modeling and simulation of the implantation. Effects of varying slotted tube stent geometry on its expansion behaviour using finite element method. The original algorithm of the ifem follows the interpolation process as illustrated in the original immersed boundary method where the fluid velocity. The pattern of the transient nonuniform stent expansion based on the four fea models is shown in figure 4. Aortic endovascular repair modeling using the finite. Stent modeling using immersed finite element method nasaads. The palmazschatz type of stent 2629 with a length of 15 mm is implanted in the middle of channel, embedded into the channel wall tightly.
Finite element analysis of a novel design for a nonmigrating biliary stent using abaqus by jared d. Mechanical behavior of coronary stents investigated through the. The initial configuration of the balloon and stent are designed and discretized using. Stent modeling using immersed finite element method article pdf available in computer methods in applied mechanics and engineering 1953336. An infilling sampling criterion named expected improvement ei is used to balance local and global searches in the optimization iteration.
Flexibility is a particularly important biomechanical property for intracranial vascular stents. Finite element analysis of mechanical behaviors of. In this section, a summary of the formulation of the immersed finite element method ifem is presented. Kafafy abstract a new particleincell algorithm was developed for plasma simulations involving complex boundary conditions. Design optimization of coronary stent based on finite.
Computer methods in applied mechanics and engineering. Four commonly used finite element models of stent dilation. The immersed finite element method ifem is a novel numerical approach to solve fluidstructure interaction types of problems that utilizes nonconforming meshing concept. Research article design optimization of coronary stent. Hence, initial evaluation using numerical methods provides an opportunity to investigate some aspects of the mechanical performance in detail. In general, the numerical approaches to model fluidstructure interactions can be classified into two categories. Pdf aortic endovascular repair modeling using the finite. Modeling of soft tissues interacting with fluid blood or. In section 4, we summarize the ifem concept, its attributes and future applications. Immersed finite element method and its applications to. The ones marked may be different from the article in the profile. Immersed methods are considered as a class of nonboundaryfitted meshing technique for simulating fluidstructure interactions. Existing stent expansion modeling methods originally developed for metallic wire mesh stent simulations were used to investigate the response of a 5 coil polymeric helical stent.
A novel large selfexpanding endovascular stent was designed with strut thickness of 70. Typical problem areas of interest include the traditional fields of structural analysis, heat transfer, fluid flow, mass transport, and electromagnetic potential. Application of periodic boundary conditions in studying. The deployment of a balloon expandable stent is simulated using immersed finite element method ifem, which was developed for solving complex fluid and deformable structure interaction problems. Similar to the immersed boundary method, the fluid domain is defined on a fixed eulerian grid. In our previous work 27, we built a computer model and simulated a balloon expandable stent interacting with its surrounding fluid using the immersed finite element method. The channel with a diameter of 3 mm and a length of 20 mm is built to represent the blood vessel. Study on flexibility of intracranial vascular stents based. Lucy t zhang mechanical, aerospace, and nuclear engineering. A 3d parallel immersed finite element particleincell framework for plasma simulations. The finite element method fem is the most widely used method for solving problems of engineering and mathematical models. In the 1970s, peskin developed the immersed boundary ib method. Four mechanical models were adopted to simulate the bending deformation of stents, and comparative studies were conducted about the distinction between cantilever beam and simply.
The aim of this work is to investigate the expansion characteristics of a stent multilink stent as it is deployed and implanted. This cited by count includes citations to the following articles in scholar. Interface treatments for immersed finite element method 2006x immersed finite element method for fluidstructure interactions 2006xangioplasty stent modeling using immersed finite element method 2006x immersed finite element method and applications to biological systems 2006xbridging scale particle and finite element methods 2005. Basedon the ife method, the immersed finite element particleincell. Hence, the concept in the mathematical modeling was very different from our stent method developed in this study by finite element analysis. Computational modeling of magnetic nanoparticle targeting. Stent material nitinol determination of characteristics.
To study the flexibility of stent, the following work was carried out by using the finite element method. Pdf the objective of this paper is to study the mechanical behaviors of angioplasty stents during and after implantation using a fluidstructure. Pdf stent modeling using immersed finite element method. There were many former studies using finite element method fem to simulate the deployment of selfexpandable lasercut stents. In a second step, a material law is deduced from the material data that is suited for use within a finite element program. An analysis of the arterial wall stresses in the stented arteries indicates that the modular s7 stent design causes lower stress to an atherosclerotic vessel with a localized stenotic lesion compared to the slotted tube nir design. This paper presents an effective optimization method using the kriging surrogate model combing with modified rectangular grid sampling to reduce the stent dogboning effect in the expansion process. Liu, stent modeling using immersed finite element method. An analysis of the arterial wall stresses in the stented arteries indicates that the modular s7 stent design causes lower stress to an atherosclerotic vessel with a localized stenotic lesion compared to the slotted tube. The fem is a particular numerical method for solving. The stents analysed using the finiteelement method were the s7 medtronic ave and the nir boston scientific stent designs. The fluid and the solid domains are represented independently.
An efficient and robust modeling technique is essential in the study of. Using this method, we model a stainless steel stent in a blood vessel. The deployment of a balloon expandable stent is simulated using the immersed finite element method ifem. However, our framework described here can be used for high order immersed interface. This straightforward finite element interpolation function for unstructured grids enables us to obtain a sharper interface that yields more accurate interfacial solutions.
Understanding the mechanical properties of selfexpandable stents. Angioplasty stent modeling using immersed finite element method. Using of finite element method and computational analysis. Modified immersed finite element method for fullycoupled fluidstructure interactions in the past few decades, numerous research efforts have been directed toward methods development of fluidstructure interactions. On computational issues of immersed finite element methods.
Application of periodic boundary conditions in studying stent. Conceptually in this study from china, where flow diversion stents were not available, the wall stents were deployed serially. The method was developed and investigated to identify a novel simpler technique in. The inner diameter of the stent is 3 mm, same as the channel diameter. Immersed interface finiteelement methods 475 triangular immersed interface. Then, effects of external magnetic field strength, magnetic particle size, and flow velocity on mnps targeting and binding have been analyzed through a parametric study. In this article, finite element method is used to investigate the mechanical behavior of a stent and to determine the biomechanical interaction between the stent and the artery in a stenting proced. A multiphysics model was developed to study the delivery of magnetic nanoparticles mnps to the stent implanted region under an external magnetic field. Using this method, we modelled a stainless steel stent in a blood vessel. Immersed approaches are different since the geometrical features of the. This paper summarizes the newly developed immersed finite element method ifem and its applications to the modeling of biological systems. In ifem, a lagrangian solid mesh moves on top of a background eulerian. Immersed finite element method and its applications to biological.
Immersed finite element particleincell simulations of ion propulsion raed i. Let us consider an incompressible threedimensional deformable structure in. We have developed a numerical model of the endovascular treatment of abdominal aortic aneurysms aaa using finite element analysis fea, we took into account the geometry of the biological region reconstructed from scans, a local characterization of the guidewirecatheter. This method is directed to the development of modeling and simulation approaches for.
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