1
|
Chekotu JC, Kinahan D, Goodall R, Brabazon D. Influence of Structural Porosity and Martensite Evolution on Mechanical Characteristics of Nitinol via In-Silico Finite Element Approach. MATERIALS (BASEL, SWITZERLAND) 2022; 15:5365. [PMID: 35955298 PMCID: PMC9369952 DOI: 10.3390/ma15155365] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/05/2022] [Revised: 07/31/2022] [Accepted: 08/02/2022] [Indexed: 02/04/2023]
Abstract
Nitinol (NiTi) alloys are gaining extensive attention due to their excellent mechanical, superelasticity, and biocompatibility properties. It is difficult to model the complex mechanical behavior of NiTi alloys due to the solid-state diffusionless phase transformations, and the differing elasticity and plasticity presenting from these two phases. In this work, an Auricchio finite element (FE) model was used to model the mechanical behavior of superelastic NiTi and was validated with experimental data from literature. A Representative Volume Element (RVE) was used to simulate the NiTi microstructure, and a microscale study was performed to understand how the evolution of martensite phase from austenite affects the response of the material upon loading. Laser Powder Bed Fusion (L-PBF) is an effective way to build complex NiTi components. Porosity being one of the major defects in Laser Powder Bed Fusion (L-PBF) processes, the model was used to correlate the macroscale effect of porosity (1.4-83.4%) with structural stiffness, dissipated energy during phase transformations, and damping properties. The results collectively summarize the effectiveness of the Auricchio model and show that this model can aid engineers to plan NiTi processing and operational parameters, for example for heat pump, medical implant, actuator, and shock absorption applications.
Collapse
Affiliation(s)
- Josiah Cherian Chekotu
- Advanced Metallic Systems Centre for Doctoral Training, I-Form Advanced Manufacturing Research Centre, Dublin City University, D09 NR58 Dublin, Ireland
- Advanced Processing Technology Research Centre, School of Mechanical and Manufacturing Engineering, Dublin City University, D09 NR58 Dublin, Ireland
| | - David Kinahan
- Advanced Metallic Systems Centre for Doctoral Training, I-Form Advanced Manufacturing Research Centre, Dublin City University, D09 NR58 Dublin, Ireland
- Advanced Processing Technology Research Centre, School of Mechanical and Manufacturing Engineering, Dublin City University, D09 NR58 Dublin, Ireland
| | - Russell Goodall
- Advanced Metallic Systems Centre for Doctoral Training, Department of Materials Science and Engineering, University of Sheffield, Sheffield S1 3JD, UK
| | - Dermot Brabazon
- Advanced Metallic Systems Centre for Doctoral Training, I-Form Advanced Manufacturing Research Centre, Dublin City University, D09 NR58 Dublin, Ireland
- Advanced Processing Technology Research Centre, School of Mechanical and Manufacturing Engineering, Dublin City University, D09 NR58 Dublin, Ireland
| |
Collapse
|
2
|
Vahabli E, Mann J, Heidari BS, Lawrence‐Brown M, Norman P, Jansen S, Pardo EDJ, Doyle B. The Technological Advancement to Engineer Next-Generation Stent-Grafts: Design, Material, and Fabrication Techniques. Adv Healthc Mater 2022; 11:e2200271. [PMID: 35481675 DOI: 10.1002/adhm.202200271] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2022] [Revised: 04/04/2022] [Indexed: 12/12/2022]
Abstract
Endovascular treatment of aortic disorders has gained wide acceptance due to reduced physiological burden to the patient compared to open surgery, and ongoing stent-graft evolution has made aortic repair an option for patients with more complex anatomies. To date, commercial stent-grafts are typically developed from established production techniques with simple design structures and limited material ranges. Despite the numerous updated versions of stent-grafts by manufacturers, the reoccurrence of device-related complications raises questions about whether the current manfacturing methods are technically able to eliminate these problems. The technology trend to produce efficient medical devices, including stent-grafts and all similar implants, should eventually change direction to advanced manufacturing techniques. It is expected that through recent advancements, especially the emergence of 4D-printing and smart materials, unprecedented features can be defined for cardiovascular medical implants, like shape change and remote battery-free self-monitoring. 4D-printing technology promises adaptive functionality, a highly desirable feature enabling printed cardiovascular implants to physically transform with time to perform a programmed task. This review provides a thorough assessment of the established technologies for existing stent-grafts and provides technical commentaries on known failure modes. They then discuss the future of advanced technologies and the efforts needed to produce next-generation endovascular implants.
Collapse
Affiliation(s)
- Ebrahim Vahabli
- Vascular Engineering Laboratory Harry Perkins Institute of Medical Research QEII Medical Centre Nedlands and the UWA Centre for Medical Research The University of Western Australia Perth 6009 Australia
- School of Engineering The University of Western Australia Perth 6009 Australia
| | - James Mann
- Vascular Engineering Laboratory Harry Perkins Institute of Medical Research QEII Medical Centre Nedlands and the UWA Centre for Medical Research The University of Western Australia Perth 6009 Australia
- School of Engineering The University of Western Australia Perth 6009 Australia
| | - Behzad Shiroud Heidari
- Vascular Engineering Laboratory Harry Perkins Institute of Medical Research QEII Medical Centre Nedlands and the UWA Centre for Medical Research The University of Western Australia Perth 6009 Australia
- School of Engineering The University of Western Australia Perth 6009 Australia
- Australian Research Council Centre for Personalised Therapeutics Technologies University of Western Australia Perth 6009 Australia
| | | | - Paul Norman
- Vascular Engineering Laboratory Harry Perkins Institute of Medical Research QEII Medical Centre Nedlands and the UWA Centre for Medical Research The University of Western Australia Perth 6009 Australia
- Medical School The University of Western Australia Perth 6009 Australia
| | - Shirley Jansen
- Curtin Medical School Curtin University Perth WA 6102 Australia
- Department of Vascular and Endovascular Surgery Sir Charles Gairdner Hospital Perth WA 6009 Australia
- Heart and Vascular Research Institute Harry Perkins Medical Research Institute Perth WA 6009 Australia
| | - Elena de Juan Pardo
- School of Engineering The University of Western Australia Perth 6009 Australia
- School of Mechanical Medical and Process Engineering Queensland University of Technology Brisbane Queensland 4059 Australia
- T3mPLATE Harry Perkins Institute of Medical Research QEII Medical Centre Nedlands and the UWA Centre for Medical Research The University of Western Australia Perth WA 6009 Australia
| | - Barry Doyle
- Vascular Engineering Laboratory Harry Perkins Institute of Medical Research QEII Medical Centre Nedlands and the UWA Centre for Medical Research The University of Western Australia Perth 6009 Australia
- School of Engineering The University of Western Australia Perth 6009 Australia
- Australian Research Council Centre for Personalised Therapeutics Technologies University of Western Australia Perth 6009 Australia
- British Heart Foundation Centre for Cardiovascular Science The University of Edinburgh Edinburgh EH16 4TJ UK
| |
Collapse
|
3
|
Characterizing the Mechanical Performance of a Bare-Metal Stent with an Auxetic Cell Geometry. APPLIED SCIENCES-BASEL 2022. [DOI: 10.3390/app12020910] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
This study develops and characterizes the distinctive mechanical features of a stainless-steel metal stent with a tailored structure. A high-precision femtosecond laser was used to micromachine a stent with re-entrant hexagonal (auxetic) cell geometry. We then characterized its mechanical behavior under various mechanical loadings using in vitro experiments and through finite element analysis. The stent properties, such as the higher capability of the stent to bear upon bending, exceptional advantage at elevated levels of twisting angles, and proper buckling, all ensured a preserved opening to maintain the blood flow. The outcomes of this preliminary study present a potential design for a stent with improved physiologically relevant mechanical conditions such as longitudinal contraction, radial strength, and migration of the stent.
Collapse
|
4
|
Hejazi M, Sassani F, Gagnon J, Hsiang Y, Phani AS. Deformation mechanics of self-expanding venous stents: Modelling and experiments. J Biomech 2021; 120:110333. [PMID: 33730560 DOI: 10.1016/j.jbiomech.2021.110333] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2020] [Accepted: 02/12/2021] [Indexed: 10/22/2022]
Abstract
Deformation properties of venous stents based on braided design, chevron design, Z design, and diamond design are compared using in vitro experiments coupled with analytical and finite element modelling. Their suitability for deployment in different clinical contexts is assessed based on their deformation characteristics. Self-expanding stainless steel stents possess superior collapse resistance compared to Nitinol stents. Consequently, they may be more reliable to treat diseases like May-Thurner syndrome in which resistance against a concentrated (pinching) force applied on the stent is needed to prevent collapse. Braided design applies a larger radial pressure particularly for vessels of diameter smaller than 75% of its nominal diameter, making it suitable for a long lesion with high recoil. Z design has the least foreshortening, which aids in accurate deployment. Nitinol stents are more compliant than their stainless steel counterparts, which indicates their suitability in veins. The semi-analytical method presented can aid in rapid assessment of topology governed deformation characteristics of stents and their design optimization.
Collapse
Affiliation(s)
- Masoud Hejazi
- Department of Mechanical Engineering, 6250 Applied Science Lane, University of British Columbia, Vancouver, B.C V6T 1Z4, Canada
| | - Farrokh Sassani
- Department of Mechanical Engineering, 6250 Applied Science Lane, University of British Columbia, Vancouver, B.C V6T 1Z4, Canada
| | - Jöel Gagnon
- Division of Vascular Surgery, 4219-2775 Laurel Street, Vancouver General Hospital, Vancouver, B.C V5Z 1M9, Canada
| | - York Hsiang
- Division of Vascular Surgery, 4219-2775 Laurel Street, Vancouver General Hospital, Vancouver, B.C V5Z 1M9, Canada
| | - A Srikantha Phani
- Department of Mechanical Engineering, 6250 Applied Science Lane, University of British Columbia, Vancouver, B.C V6T 1Z4, Canada.
| |
Collapse
|
5
|
Kumar A, Bhatnagar N. Finite element simulation and testing of cobalt-chromium stent: a parametric study on radial strength, recoil, foreshortening, and dogboning. Comput Methods Biomech Biomed Engin 2020; 24:245-259. [PMID: 33021106 DOI: 10.1080/10255842.2020.1822823] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
The effectiveness of cardiovascular stenting procedure depends on the crimping and expansion characteristics of a stent, influenced by its design parameters. In this study, CoCr stents are fabricated, crimped on a tri-folded balloon, and expanded using manual inflation device. Similarly, in the finite element model, a tri-folded balloon is used to expand the stent. The length and diameter are measured to evaluate the radial strength, recoil, foreshortening, and dogboning. The simulation and experimental results match satisfactorily. The validated FE model can be used with confidence to optimize future stent designs, thus reducing the number of testing and product development time.
Collapse
Affiliation(s)
- Avinash Kumar
- Department of Mechanical Engineering, Indian Institute of Technology-Delhi, New Delhi, India
| | - Naresh Bhatnagar
- Department of Mechanical Engineering, Indian Institute of Technology-Delhi, New Delhi, India
| |
Collapse
|
6
|
PANNEERSELVAM NISANTHKUMAR, MUTHUSWAMY SREEKUMAR. DESIGN AND ANALYSIS OF NEW STENT PATTERNS FOR ENHANCED PERFORMANCE. J MECH MED BIOL 2020. [DOI: 10.1142/s0219519420500396] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Deploying a stent to restore blood flow in the coronary artery is very complicated, as its internal diameter is smaller than 3[Formula: see text]mm. It has already been proven that mechanical stresses induced on stent and artery during deployment make the placement of stent very difficult, besides the development of complications due to artery damage. Various stent designs have already been developed, especially in the metallic category. Still, there are possibilities for developing new stent designs and patterns to overcome the complexities of the existing models. Also, the technology of metallic stents can be carried forward towards the development of bioresorbable polymeric stents. In this work, three new stent cell designs (curvature, diamond, and oval) have been proposed to obtain better performance and life. The finite element method is utilized to explore the mechanical behavior of stent expansion and determine the biomechanical stresses imposed on the stent and artery during the stenting procedure. The results obtained have been compared with the available literature and found that the curvature cell design develops lower stresses and, hence, be suitable for better performance and life.
Collapse
Affiliation(s)
- NISANTHKUMAR PANNEERSELVAM
- Department of Mechanical Engineering, Indian Institute of Information Technology, Design and Manufacturing, Kancheepuram Chennai 600127, India
| | - SREEKUMAR MUTHUSWAMY
- Department of Mechanical Engineering, Indian Institute of Information Technology, Design and Manufacturing, Kancheepuram Chennai 600127, India
| |
Collapse
|
7
|
Geith MA, Swidergal K, Hochholdinger B, Schratzenstaller TG, Wagner M, Holzapfel GA. On the importance of modeling balloon folding, pleating, and stent crimping: An FE study comparing experimental inflation tests. INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN BIOMEDICAL ENGINEERING 2019; 35:e3249. [PMID: 31400057 PMCID: PMC9285761 DOI: 10.1002/cnm.3249] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/29/2019] [Revised: 07/23/2019] [Accepted: 08/03/2019] [Indexed: 06/10/2023]
Abstract
Finite element (FE)-based studies of preoperative processes such as folding, pleating, and stent crimping with a comparison with experimental inflation tests are not yet available. Therefore, a novel workflow is presented in which residual stresses of balloon folding and pleating, as well as stent crimping, and the geometries of all contact partners were ultimately implemented in an FE code to simulate stent expansion by using an implicit solver. The numerical results demonstrate that the incorporation of residual stresses and strains experienced during the production step significantly increased the accuracy of the subsequent simulations, especially of the stent expansion model. During the preoperative processes, stresses inside the membrane and the stent material also reached a rather high level. Hence, there can be no presumption that balloon catheters or stents are undamaged before the actual surgery. The implementation of the realistic geometry, in particular the balloon tapers, and the blades of the process devices improved the simulation of the expansion mechanisms, such as dogboning, concave bending, or overexpansion of stent cells. This study shows that implicit solvers are able to precisely simulate the mentioned preoperative processes and the stent expansion procedure without a preceding manipulation of the simulation time or physical mass.
Collapse
Affiliation(s)
- Markus A. Geith
- Institute of BiomechanicsGraz University of TechnologyGrazAustria
- Biomedical Engineering DepartmentKing's College LondonUnited Kingdom
- Faculty of Mechanical EngineeringOstbayerische Technische Hochschule RegensburgGermany
| | - Krzysztof Swidergal
- Faculty of Mechanical EngineeringOstbayerische Technische Hochschule RegensburgGermany
| | | | | | - Marcus Wagner
- Faculty of Mechanical EngineeringOstbayerische Technische Hochschule RegensburgGermany
| | - Gerhard A. Holzapfel
- Institute of BiomechanicsGraz University of TechnologyGrazAustria
- Department of Structural EngineeringNorwegian University of Science and TechnologyTrondheimNorway
| |
Collapse
|
8
|
Wiesent L, Schultheiß U, Schmid C, Schratzenstaller T, Nonn A. Experimentally validated simulation of coronary stents considering different dogboning ratios and asymmetric stent positioning. PLoS One 2019; 14:e0224026. [PMID: 31626662 PMCID: PMC6799901 DOI: 10.1371/journal.pone.0224026] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2019] [Accepted: 10/03/2019] [Indexed: 11/20/2022] Open
Abstract
In-stent restenosis remains a major problem of arteriosclerosis treatment by stenting. Expansion-optimized stents could reduce this problem. With numerical simulations, stent designs/ expansion behaviours can be effectively analyzed. For reasons of efficiency, simplified models of balloon-expandable stents are often used, but their accuracy must be challenged due to insufficient experimental validation. In this work, a realistic stent life-cycle simulation has been performed including balloon folding, stent crimping and free expansion of the balloon-stent-system. The successful simulation and validation of two stent designs with homogenous and heterogeneous stent stiffness and an asymmetrically positioned stent on the balloon catheter confirm the universal applicability of the simulation approach. Dogboning ratio, as well as the final dimensions of the folded balloon, the crimped and expanded stent, correspond well to the experimental dimensions with only slight deviations. In contrast to the detailed stent life-cycle simulation, a displacement-controlled simulation can not predict the transient stent expansion, but is suitable to reproduce the final expanded stent shape and the associated stress states. The detailed stent life-cycle simulation is thus essential for stent expansion analysis/optimization, whereas for reasons of computational efficiency, the displacement-controlled approach can be considered in the context of pure stress analysis.
Collapse
Affiliation(s)
- Lisa Wiesent
- Computational Mechanics and Materials Lab, Ostbayerische Technische Hochschule (OTH) Regensburg, Regensburg, Germany
- Regensburg Center of Biomedical Engineering (RCBE), Regensburg, Germany
- Medical Device Lab, OTH Regensburg, Regensburg, Germany
- * E-mail:
| | - Ulrich Schultheiß
- Material Science and Surface Analytics Lab, OTH Regensburg, Regensburg, Germany
| | - Christof Schmid
- University Hospital Regensburg, Cardiothoracic and Cardiovascular Surgery, Regensburg, Germany
| | - Thomas Schratzenstaller
- Regensburg Center of Biomedical Engineering (RCBE), Regensburg, Germany
- Medical Device Lab, OTH Regensburg, Regensburg, Germany
| | - Aida Nonn
- Computational Mechanics and Materials Lab, Ostbayerische Technische Hochschule (OTH) Regensburg, Regensburg, Germany
| |
Collapse
|
9
|
Azarnoush H, Pazos V, Vergnole S, Boulet B, Lamouche G. Intravascular optical coherence tomography to validate finite-element simulation of angioplasty balloon inflation. Phys Med Biol 2019; 64:095011. [PMID: 30840938 DOI: 10.1088/1361-6560/ab0d58] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Concrete methods are lacking to examine angioplasty simulation results. For the first time, we explored the application of intravascular optical coherence tomography (IVOCT) to experimentally validate results obtained from finite-element simulation of angioplasty balloon deployment. In order to simulate each experimental scenario, IVOCT images were used to create initial geometrical models for the balloon and the phantoms. The study comprised three scenarios. The first scenario involved experimentally monitoring as well as simulating free expansion of the balloon. The second scenario involved experimentally monitoring as well as simulating balloon inflation inside three artery phantoms with different mechanical properties. The third scenario involved experimentally monitoring as well as simulating balloon unfolding and inflation inside a multilayer phantom. Using the first scenario, a constitutive model was developed for the balloon and was tuned to fit the IVOCT balloon inflation monitoring results. This model was used to simulate the balloon's response in simulations involving phantoms corresponding to the second and third scenarios. Diameter values were calculated both from images and simulation results. These values were then compared for each scenario. The obtained results highlight the potentials of IVOCT monitoring to validate simulation procedures.
Collapse
Affiliation(s)
- Hamed Azarnoush
- Amirkabir University of Technology (Tehran Polytechnic), Tehran, Iran. McGill University, Centre for Intelligent Machines, Montreal, Canada. Author to whom any correspondence may be addressed
| | | | | | | | | |
Collapse
|
10
|
Kumar GP, Yuan S, Cui F, Branicio PS, Jafary-Zadeh M. Nanoglass-based balloon expandable stents. J Biomed Mater Res B Appl Biomater 2019; 108:73-79. [PMID: 30895727 DOI: 10.1002/jbm.b.34367] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2018] [Revised: 01/30/2019] [Accepted: 02/27/2019] [Indexed: 12/17/2022]
Abstract
Here, a prototypical metallic nanoglass is proposed as a new alloy for balloon expandable stents. Traditionally, the stainless steel SS 316L alloy has been used as a preferred material for this application due to its proper combination of mechanical properties, corrosion resistance, and biocompatibility. Recently, metallic glasses (MGs) have been considered as promising materials for biodevice applications. MGs often display outstanding mechanical properties superior to those of conventional metallic alloys and overcome some of the weaknesses of SS 316L, such as radiopacity, stainless steel allergy, and thrombosis-induced restenosis. However, commonly used monolithic MGs, which have an amorphous homogeneous microstructure, suffer from lack of ductility that is necessary for deployment of balloon expandable stents. In contrast, nanoglasses, that is, amorphous alloys with heterogeneous microstructure, exhibit enhanced ductility which makes them promising materials for balloon expandable stents. We evaluate the feasibility of a prototypical Zr64 Cu36 nanoglass with a grain size of 5 nm for balloon expandable stents by performing finite element method modeling of the stent deployment process in a coronary artery. We consider the BX-Velocity stent design and the nanoglass mechanical properties calculated from atomistic simulations. The results suggest that nanoglasses are suitable materials for balloon expandable stent applications. © 2019 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 108B:73-79, 2020.
Collapse
Affiliation(s)
| | - Suyue Yuan
- Mork Family Department of Chemical Engineering and Material Science, University of Southern California, Los Angeles, California, 90089-0241
| | - Fangsen Cui
- Institute of High Performance Computing, A*STAR, Singapore, 138632
| | - Paulo Sergio Branicio
- Mork Family Department of Chemical Engineering and Material Science, University of Southern California, Los Angeles, California, 90089-0241
| | | |
Collapse
|
11
|
Karanasiou GS, Tachos NS, Sakellarios A, Michalis LK, Conway C, Edelman ER, Fotiadis DI. In silico assessment of the effects of material on stent deployment. PROCEEDINGS. IEEE INTERNATIONAL SYMPOSIUM ON BIOINFORMATICS AND BIOENGINEERING 2018; 2017:462-467. [PMID: 30079407 DOI: 10.1109/bibe.2017.00-11] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Coronary stents are expandable scaffolds that are used to widen occluded diseased arteries and restore blood flow. Because of the strain they are exposed to and forces they must resist as well as the importance of surface interactions, material properties are dominant. Indeed, a common differentiating factors amongst commercially available stents is their material. Several performance requirements relate to stent materials including radial strength for adequate arterial support post-deployment. This study investigated the effect of the stent material in three finite element models using different stents made of: (i) Cobalt-Chromium (CoCr), (ii) Stainless Steel (SS316L), and (iii) Platinum Chromium (PtCr). Deployment was investigated in a patient specific arterial geometry, created based on a fusion of angiographic data and intravascular ultrasound images. In silico results show that: (i) the maximum von Mises stress occurs for the CoCr, however the curved areas of the stent links present higher stresses compared to the straight stent segments for all stents, (ii) more areas of high inner arterial stress exist in the case of the CoCr stent deployment, (iii) there is no significant difference in the percentage of arterial stress volume distribution among all models.
Collapse
Affiliation(s)
- Georgia S Karanasiou
- Department of Biomedical Research, Institute of Molecular Biology and Biotechnology, FORTH Ioannina, Greece,
| | - Nikolaos S Tachos
- Department of Biomedical Research, Institute of Molecular Biology and Biotechnology, FORTH Ioannina, Greece
| | - Antonios Sakellarios
- Department of Biomedical Research, Institute of Molecular Biology and Biotechnology, FORTH Ioannina, Greece
| | - Lampros K Michalis
- Department of Cardiology, Medical School, University of Ioannina, Ioannina, Greece
| | - Claire Conway
- Institute for Medical Engineering and Science, Massachusetts Institute of Technology, Cambridge, MA, CBSET, Lexington, MA, USA.
| | - Elazer R Edelman
- Institute for Medical Engineering and Science, Massachusetts Institute of Technology, Cambridge, MACBSET, Lexington, MA, USA.
| | - Dimitrios I Fotiadis
- University of Ioannina, Department of Materials Science, Unit of Medical Technology and Intelligent Information Systems
| |
Collapse
|
12
|
Syaifudin A, Takeda R, Sasaki K. Development of asymmetric stent for treatment of eccentric plaque. Biomed Mater Eng 2018; 29:299-317. [PMID: 29578470 DOI: 10.3233/bme-181737] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
The selection of stent and balloon type is decisive in the stenting process. In the treatment of an eccentric plaque obstruction, a symmetric expansion from stent dilatation generates nonuniform stress distribution, which may aggravate fibrous cap prone to rupture. This paper developed a new stent design to treat eccentric plaque using structural transient dynamic analysis in ANSYS. A non-symmetric structural geometry of stent is generated to obtain reasonable stress distribution safe for the arterial layer surrounding the stent. To derive the novel structural geometry, a Sinusoidal stent type is modified by varying struts length and width, adding bridges, and varying curvature width of struts. An end ring of stent struts was also modified to eliminate dogboning phenomenon and to reduce the Ectropion angle. Two balloon types were used to deploy the stent, an ordinary cylindrical and offset balloon. Positive modification results were used to construct the final non-symmetric stent design, called an Asymmetric stent. Analyses of the deformation characteristics, changes in surface roughness and induced stresses within intact arterial layer were subsequently examined. Interaction between the stent and vessel wall was implemented by means of changes in surface roughness and stress distribution analyses. The Palmaz and the Sinusoidal stent were used for a comparative study. This study indicated that the Asymmetric stent types reduced the central radial recoiling and the dogboning phenomenon. In terms of changes in surface roughness and induced stresses, the Asymmetric stent has a comparable effect with that of the Sinusoidal stent. In addition, it could enhance the distribution of surface roughening as expanded by an offset balloon.
Collapse
Affiliation(s)
- Achmad Syaifudin
- Department of Mechanical Engineering, Institut Teknologi Sepuluh Nopember, Surabaya, Indonesia
| | - Ryo Takeda
- Division of Human Mechanical Systems and Design, Faculty of Engineering, Hokkaido University, Sapporo, Japan
| | - Katsuhiko Sasaki
- Division of Human Mechanical Systems and Design, Faculty of Engineering, Hokkaido University, Sapporo, Japan
| |
Collapse
|
13
|
Jafary-Zadeh M, Praveen Kumar G, Branicio PS, Seifi M, Lewandowski JJ, Cui F. A Critical Review on Metallic Glasses as Structural Materials for Cardiovascular Stent Applications. J Funct Biomater 2018; 9:E19. [PMID: 29495521 PMCID: PMC5872105 DOI: 10.3390/jfb9010019] [Citation(s) in RCA: 46] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2017] [Revised: 02/05/2018] [Accepted: 02/22/2018] [Indexed: 01/20/2023] Open
Abstract
Functional and mechanical properties of novel biomaterials must be carefully evaluated to guarantee long-term biocompatibility and structural integrity of implantable medical devices. Owing to the combination of metallic bonding and amorphous structure, metallic glasses (MGs) exhibit extraordinary properties superior to conventional crystalline metallic alloys, placing them at the frontier of biomaterials research. MGs have potential to improve corrosion resistance, biocompatibility, strength, and longevity of biomedical implants, and hence are promising materials for cardiovascular stent applications. Nevertheless, while functional properties and biocompatibility of MGs have been widely investigated and validated, a solid understanding of their mechanical performance during different stages in stent applications is still scarce. In this review, we provide a brief, yet comprehensive account on the general aspects of MGs regarding their formation, processing, structure, mechanical, and chemical properties. More specifically, we focus on the additive manufacturing (AM) of MGs, their outstanding high strength and resilience, and their fatigue properties. The interconnection between processing, structure and mechanical behaviour of MGs is highlighted. We further review the main categories of cardiovascular stents, the required mechanical properties of each category, and the conventional materials have been using to address these requirements. Then, we bridge between the mechanical requirements of stents, structural properties of MGs, and the corresponding stent design caveats. In particular, we discuss our recent findings on the feasibility of using MGs in self-expandable stents where our results show that a metallic glass based aortic stent can be crimped without mechanical failure. We further justify the safe deployment of this stent in human descending aorta. It is our intent with this review to inspire biodevice developers toward the realization of MG-based stents.
Collapse
Affiliation(s)
- Mehdi Jafary-Zadeh
- Institute of High Performance Computing, A*STAR, Singapore 138632, Singapore.
| | | | - Paulo Sergio Branicio
- Mork Family Department of Chemical Engineering and Materials Science, University of Southern California, Los Angeles, CA 90089-0241, USA.
| | - Mohsen Seifi
- Department of Materials Science and Engineering, Case Western Reserve University, Cleveland, OH 44106, USA.
| | - John J Lewandowski
- Department of Materials Science and Engineering, Case Western Reserve University, Cleveland, OH 44106, USA.
| | - Fangsen Cui
- Institute of High Performance Computing, A*STAR, Singapore 138632, Singapore.
| |
Collapse
|
14
|
Bukala J, Kwiatkowski P, Malachowski J. Numerical analysis of crimping and inflation process of balloon-expandable coronary stent using implicit solution. INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN BIOMEDICAL ENGINEERING 2017; 33. [PMID: 28425201 DOI: 10.1002/cnm.2890] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/14/2016] [Revised: 03/01/2017] [Accepted: 04/15/2017] [Indexed: 06/07/2023]
Abstract
The paper presents an applied methodology for numerical finite element analysis of coronary stent crimping and the free inflation process with the use of a folded noncompliant angioplasty balloon. The use of an implicit scheme is considered as the most original part of the work, as an explicit finite element procedure is very often preferred. Hitherto, when the implicit solution was used for the finite element solution, the simulated issue was largely simplified. Therefore, the authors focused on the modelling methodology with minimum possible simplification, ie, a full load path (compression and inflation in single analysis), solid element discretization, and sophisticated contact models (bodies with highly different stiffness). The obtained results are partially compared with experimental data (radial force during the crimping procedure) and present satisfactory compliance. The authors believe that presented methodology allow for significant improvement of the obtained results, as well as potential extension of the research scope, compared to previous efforts performed using the explicit integration scheme. Moreover, the presented methodology is believed to be suitable for sensitivity and optimization studies.
Collapse
Affiliation(s)
- Jakub Bukala
- Department of Mechanics and Applied Computer Science, Military University of Technology, Gen. Sylwestra Kaliskiego 2, Warsaw, 00-908, Poland
| | - Piotr Kwiatkowski
- Clinical Department of Interventional Cardiology, Central Clinical Hospital Ministry of Interior, Woloska 137, Warsaw, 02-507, Poland
| | - Jerzy Malachowski
- Department of Mechanics and Applied Computer Science, Military University of Technology, Gen. Sylwestra Kaliskiego 2, Warsaw, 00-908, Poland
| |
Collapse
|
15
|
A biaxial strain-based expansion mechanism for auxetic stent deployment. J Appl Biomater Funct Mater 2017; 15:e196-e205. [PMID: 28759102 DOI: 10.5301/jabfm.5000326] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/02/2016] [Indexed: 11/20/2022] Open
Abstract
BACKGROUND Auxetics, a special class of materials, tend to expand both in the radial and longitudinal directions when a unidirectional tensile force is applied. Recently, studies have come up with new designs for auxetic vascular and nonvascular stents which are deployed with commercial balloon catheters. There are some inherent limitations associated with a unidirectional application of expansion force in the effective deployment of stents. This work proposed a solution to some of these limitations through the use of a biaxial mode of a predetermined strain-based expansion mechanism. METHOD The design incorporated a pressure-activated crank-slider mechanism. Fabrication of a prototype for experimental verification was carried out through milling and high-speed lathe machining. The testing of the device employed the use of auxetic stents, fabricated from a biocompatible polymer. A finite element study is presented to extrapolate experimental results to a broader range of operation and working conditions. RESULTS AND CONCLUSIONS The expansion mechanism is similar in operation to the opening of an umbrella. The length of the connected auxetic stent increases when internal hydraulic pressure is applied. The degree of linear expansion in 1 direction influences the expansion of auxetic stent in the lateral direction. As the device exerts pressure longitudinally, a larger amount of the force is distributed on the unit cells/hinges which ultimately results in an increased expansion of the stent.
Collapse
|
16
|
Jia H, Hu S, Liu H, Zhu Y, Zhe CY, Li L, Mustafina I, Hou J, Zhang S, Yu B. Chronic total occlusion is associated with a higher incidence of malapposition and uncovered stent struts: OCT findings at 6 months following DES implantation. Catheter Cardiovasc Interv 2017; 89:582-591. [PMID: 28318139 DOI: 10.1002/ccd.26969] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/14/2016] [Accepted: 01/16/2017] [Indexed: 11/09/2022]
Affiliation(s)
- Haibo Jia
- Department of Cardiology; 2nd Affiliated Hospital of Harbin Medical University; Harbin People's Republic of China
- The Key Laboratory of Myocardial Ischemia, Chinese Ministry of Education; Harbin People's Republic of China
| | - Sining Hu
- Department of Cardiology; 2nd Affiliated Hospital of Harbin Medical University; Harbin People's Republic of China
- The Key Laboratory of Myocardial Ischemia, Chinese Ministry of Education; Harbin People's Republic of China
| | - Huimin Liu
- Department of Cardiology; 2nd Affiliated Hospital of Harbin Medical University; Harbin People's Republic of China
- The Key Laboratory of Myocardial Ischemia, Chinese Ministry of Education; Harbin People's Republic of China
| | - Yinchun Zhu
- Department of Cardiology; 2nd Affiliated Hospital of Harbin Medical University; Harbin People's Republic of China
- The Key Laboratory of Myocardial Ischemia, Chinese Ministry of Education; Harbin People's Republic of China
| | - Chun-yang Zhe
- Department of Cardiology; 2nd Affiliated Hospital of Harbin Medical University; Harbin People's Republic of China
- The Key Laboratory of Myocardial Ischemia, Chinese Ministry of Education; Harbin People's Republic of China
| | - Lulu Li
- Department of Cardiology; 2nd Affiliated Hospital of Harbin Medical University; Harbin People's Republic of China
- The Key Laboratory of Myocardial Ischemia, Chinese Ministry of Education; Harbin People's Republic of China
| | - Irina Mustafina
- Department of Cardiology; 2nd Affiliated Hospital of Harbin Medical University; Harbin People's Republic of China
- The Key Laboratory of Myocardial Ischemia, Chinese Ministry of Education; Harbin People's Republic of China
| | - Jingbo Hou
- Department of Cardiology; 2nd Affiliated Hospital of Harbin Medical University; Harbin People's Republic of China
- The Key Laboratory of Myocardial Ischemia, Chinese Ministry of Education; Harbin People's Republic of China
| | - Shaosong Zhang
- Department of Cardiology; 2nd Affiliated Hospital of Harbin Medical University; Harbin People's Republic of China
- The Key Laboratory of Myocardial Ischemia, Chinese Ministry of Education; Harbin People's Republic of China
| | - Bo Yu
- Department of Cardiology; 2nd Affiliated Hospital of Harbin Medical University; Harbin People's Republic of China
- The Key Laboratory of Myocardial Ischemia, Chinese Ministry of Education; Harbin People's Republic of China
| |
Collapse
|
17
|
Lim YH, Jeong HY. Finite element analyses for improved design of peripheral stents. Comput Methods Biomech Biomed Engin 2017; 20:653-662. [PMID: 28349767 DOI: 10.1080/10255842.2017.1286650] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
Due to the recent increase in the number of stent insertion procedures, the number of studies to evaluate the mechanical behaviors of stents, such as the stress and deformation states, using finite element analysis is also increasing. However, it is still not easy to design stents that are uniformly expanded and show enough radial strength and flexibility. Therefore, in this study, the Taguchi method and finite element analysis were used to determine a set of optimal design variables for unit patterns of stents, and a new design approach was developed to realize uniform expansion, enough radial strength and good flexibility. The stent designed using the new design approach was verified by experiments.
Collapse
Affiliation(s)
- Yong-Hyun Lim
- a Department of Mechanical Engineering , Sogang University , Seoul , Republic of Korea
| | - Hyun-Yong Jeong
- a Department of Mechanical Engineering , Sogang University , Seoul , Republic of Korea
| |
Collapse
|
18
|
Stents: Biomechanics, Biomaterials, and Insights from Computational Modeling. Ann Biomed Eng 2017; 45:853-872. [PMID: 28160103 DOI: 10.1007/s10439-017-1806-8] [Citation(s) in RCA: 38] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2016] [Accepted: 01/28/2017] [Indexed: 01/02/2023]
|
19
|
Li H, Wang X, Wei Y, Liu T, Gu J, Li Z, Wang M, Zhao D, Qiao A, Liu Y. Multi-Objective Optimizations of Biodegradable Polymer Stent Structure and Stent Microinjection Molding Process. Polymers (Basel) 2017; 9:polym9010020. [PMID: 30970706 PMCID: PMC6432066 DOI: 10.3390/polym9010020] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2016] [Revised: 12/26/2016] [Accepted: 12/30/2016] [Indexed: 11/16/2022] Open
Abstract
Biodegradable stents made of poly-l-lactic acid (PLLA) have a promising prospect thanks to high biocompatibility and a favorable biodegradation period. However, due to the low stiffness of PLLA, polymeric stents have a lower radial stiffness and larger foreshortening. Furthermore, a stent is a tiny meshed tube, hence, it is difficult to make a polymeric stent. In the present study, a finite element analysis-based optimization method combined with Kriging surrogate modeling is firstly proposed to optimize the stent structure and stent microinjection molding process, so as to improve the stent mechanical properties and microinjection molding quality, respectively. The Kriging surrogate models are constructed to formulate the approximate mathematical relationships between the design variables and design objectives. Expected improvement is employed to balance local and global search to find the global optimal design. As an example, the polymeric ART18Z stent was investigated. The mechanical properties of stent expansion in a stenotic artery and the molding quality were improved after optimization. Numerical results demonstrate the proposed optimization method can be used for the computationally measurable optimality of stent structure design and stent microinjection molding process.
Collapse
Affiliation(s)
- Hongxia Li
- School of Mechanical Engineering, Dalian University of Technology, Dalian 116023, China.
| | - Xinyu Wang
- School of Mechanical Engineering, Dalian University of Technology, Dalian 116023, China.
| | - Yunbo Wei
- School of Mechanical Engineering, Dalian University of Technology, Dalian 116023, China.
| | - Tao Liu
- School of Mechanical Engineering, Dalian University of Technology, Dalian 116023, China.
| | - Junfeng Gu
- Department of Engineering Mechanics, State Key Laboratory of Structural Analysis for Industrial Equipment, Dalian University of Technology, Dalian 116023, China.
| | - Zheng Li
- Department of Engineering Mechanics, State Key Laboratory of Structural Analysis for Industrial Equipment, Dalian University of Technology, Dalian 116023, China.
| | - Minjie Wang
- School of Mechanical Engineering, Dalian University of Technology, Dalian 116023, China.
| | - Danyang Zhao
- School of Mechanical Engineering, Dalian University of Technology, Dalian 116023, China.
| | - Aike Qiao
- College of Life Science and Bioengineering, Beijing University of Technology, Beijing 100124, China.
| | - Yahua Liu
- School of Mechanical Engineering, Dalian University of Technology, Dalian 116023, China.
| |
Collapse
|
20
|
Li H, Liu T, Wang M, Zhao D, Qiao A, Wang X, Gu J, Li Z, Zhu B. Design optimization of stent and its dilatation balloon using kriging surrogate model. Biomed Eng Online 2017; 16:13. [PMID: 28086895 PMCID: PMC5234108 DOI: 10.1186/s12938-016-0307-6] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2016] [Accepted: 12/25/2016] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Although stents have great success of treating cardiovascular disease, it actually undermined by the in-stent restenosis and their long-term fatigue failure. The geometry of stent affects its service performance and ultimately affects its fatigue life. Besides, improper length of balloon leads to transient mechanical injury to the vessel wall and in-stent restenosis. Conventional optimization method of stent and its dilatation balloon by comparing several designs and choosing the best one as the optimal design cannot find the global optimal design in the design space. In this study, an adaptive optimization method based on Kriging surrogate model was proposed to optimize the structure of stent and the length of stent dilatation balloon so as to prolong stent service life and improve the performance of stent. METHODS A finite element simulation based optimization method combing with Kriging surrogate model is proposed to optimize geometries of stent and length of stent dilatation balloon step by step. Kriging surrogate model coupled with design of experiment method is employed to construct the approximate functional relationship between optimization objectives and design variables. Modified rectangular grid is used to select initial training samples in the design space. Expected improvement function is used to balance the local and global searches to find the global optimal result. Finite element method is adopted to simulate the free expansion of balloon-expandable stent and the expansion of stent in stenotic artery. The well-known Goodman diagram was used for the fatigue life prediction of stent, while dogboning effect was used for stent expansion performance measurement. As the real design cases, diamond-shaped stent and sv-shaped stent were studied to demonstrate how the proposed method can be harnessed to design and refine stent fatigue life and expansion performance computationally. RESULTS The fatigue life and expansion performance of both the diamond-shaped stent and sv-shaped stent are designed and refined, respectively. (a) diamond-shaped stent: The shortest distance from the data points to the failure line in the Goodman diagram was increased by 22.39%, which indicated a safer service performance of the optimal stent. The dogboning effect was almost completely eliminated, which implies more uniform expansion of stent along its length. Simultaneously, radial elastic recoil (RR) at the proximal and distal ends was reduced by 40.98 and 35% respectively and foreshortening (FS) was also decreased by 1.75%. (b) sv-shaped stent: The shortest distance from the data point to the failure line in the Goodman diagram was increased by 15.91%. The dogboning effect was also completely eliminated, RR at the proximal and distal ends was reduced by 82.70 and 97.13%, respectively, and the FS was decreased by 16.81%. Numerical results showed that the fatigue life of both stents was refined and the comprehensive expansion performance of them was improved. CONCLUSIONS This article presents an adaptive optimization method based on the Kriging surrogate model to optimize the structure of stents and the length of their dilatation balloon to prolong stents fatigue life and decreases the dogboning effect of stents during expansion process. Numerical results show that the adaptive optimization method based on Kriging surrogate model can effectively optimize the design of stents and the dilatation balloon. Further investigations containing more design goals and more effective multidisciplinary design optimization method are warranted.
Collapse
Affiliation(s)
- Hongxia Li
- School of Mechanical Engineering, Dalian University of Technology, Dalian, 116023, Liaoning, China
| | - Tao Liu
- School of Mechanical Engineering, Dalian University of Technology, Dalian, 116023, Liaoning, China
| | - Minjie Wang
- School of Mechanical Engineering, Dalian University of Technology, Dalian, 116023, Liaoning, China
| | - Danyang Zhao
- School of Mechanical Engineering, Dalian University of Technology, Dalian, 116023, Liaoning, China
| | - Aike Qiao
- College of Life Science and Bioengineering, Beijing University of Technology, Beijing, 100124, China
| | - Xue Wang
- Mechanical Engineering and Material Science Department, University of Pittsburgh, 4200 Fifth Avenue, Pittsburgh, PA, 15260, USA
| | - Junfeng Gu
- Department of Engineering Mechanics, State Key Laboratory of Structural Analysis for Industrial Equipment, Dalian University of Technology, Dalian, 116023, Liaoning, China
| | - Zheng Li
- Department of Engineering Mechanics, State Key Laboratory of Structural Analysis for Industrial Equipment, Dalian University of Technology, Dalian, 116023, Liaoning, China
| | - Bao Zhu
- School of Materials Science and Engineering, Dalian University of Technology, No. 2, Linggong Road, Dalian, 116024, Liaoning, China.
| |
Collapse
|
21
|
A new structure-property connection in the skeletal elements of the marine sponge Tethya aurantia that guards against buckling instability. Sci Rep 2017; 7:39547. [PMID: 28051108 PMCID: PMC5209657 DOI: 10.1038/srep39547] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2016] [Accepted: 11/24/2016] [Indexed: 11/08/2022] Open
Abstract
We identify a new structure-property connection in the skeletal elements of the marine sponge Tethya aurantia. The skeletal elements, known as spicules, are millimeter-long, axisymmetric, silica rods that are tapered along their lengths. Mechanical designs in other structural biomaterials, such as nacre and bone, have been studied primarily for their benefits to toughness properties. The structure-property connection we identify, however, falls in the entirely new category of buckling resistance. We use computational mechanics calculations and information about the spicules' arrangement within the sponge to develop a structural mechanics model for the spicules. We use our structural mechanics model along with measurements of the spicules' shape to estimate the load they can transmit before buckling. Compared to a cylinder with the same length and volume, we predict that the spicules' shape enhances this critical load by up to 30%. We also find that the spicules' shape is close to the shape of the column that is optimized to transmit the largest load before buckling. In man-made structures, many strategies are used to prevent buckling. We find, however, that the spicules use a completely new strategy. We hope our discussion will generate a greater appreciation for nature's ability to produce beneficial designs.
Collapse
|
22
|
Amir Paisal MS, Taib I, Ismail AE. Computational Analysis on Stent Geometries in Carotid Artery: A Review. IOP CONFERENCE SERIES: MATERIALS SCIENCE AND ENGINEERING 2017; 165:012003. [DOI: 10.1088/1757-899x/165/1/012003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/01/2023]
|
23
|
Li H, Gu J, Wang M, Zhao D, Li Z, Qiao A, Zhu B. Multi-objective optimization of coronary stent using Kriging surrogate model. Biomed Eng Online 2016; 15:148. [PMID: 28155700 PMCID: PMC5260142 DOI: 10.1186/s12938-016-0268-9] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
Background In stent design optimization, the functional relationship between design parameters and design goals is nonlinear, complex, and implicit and the multi-objective design of stents involves a number of potentially conflicting performance criteria. Therefore it is hard and time-consuming to find the optimal design of stent either by experiment or clinic test. Fortunately, computational methods have been developed to the point whereby optimization and simulation tools can be used to systematically design devices in a realistic time-scale. The aim of the present study is to propose an adaptive optimization method of stent design to improve its expansion performance. Methods Multi-objective optimization method based on Kriging surrogate model was proposed to decrease the dogboning effect and the radial elastic recoil of stents to improve stent expansion properties and thus reduce the risk of vascular in-stent restenosis injury. Integrating design of experiment methods and Kriging surrogate model were employed to construct the relationship between measures of stent dilation performance and geometric design parameters. Expected improvement, an infilling sampling criterion, was employed to balance local and global search with the aim of finding the global optimal design. A typical diamond-shaped coronary stent-balloon system was taken as an example to test the effectiveness of the optimization method. Finite element method was used to analyze the stent expansion of each design. Results 27 iterations were needed to obtain the optimal solution. The absolute values of the dogboning ratio at 32 and 42 ms were reduced by 94.21 and 89.43%, respectively. The dogboning effect was almost eliminated after optimization. The average of elastic recoil was reduced by 15.17%. Conclusion This article presents FEM based multi-objective optimization method combining with the Kriging surrogate model to decrease both the dogboning effect and radial elastic recoil of stents. The numerical results prove that the proposed optimization method effectively decreased both the dogboning effect and radial elastic recoil of stent. Further investigations containing more design goals and more effective multidisciplinary design optimization method are warranted.
Collapse
Affiliation(s)
- Hongxia Li
- School of Mechanical Engineering, Dalian University of Technology, Dalian, 116023, Liaoning, China
| | - Junfeng Gu
- State Key Laboratory of Structural Analysis for Industrial Equipment, Department of Engineering Mechanics, Dalian University of Technology, Dalian, 116023, Liaoning, China
| | - Minjie Wang
- School of Mechanical Engineering, Dalian University of Technology, Dalian, 116023, Liaoning, China
| | - Danyang Zhao
- School of Mechanical Engineering, Dalian University of Technology, Dalian, 116023, Liaoning, China
| | - Zheng Li
- State Key Laboratory of Structural Analysis for Industrial Equipment, Department of Engineering Mechanics, Dalian University of Technology, Dalian, 116023, Liaoning, China
| | - Aike Qiao
- College of Life Science and Bioengineering, Beijing University of Technology, Beijing, 100124, China
| | - Bao Zhu
- School of Materials Science and Engineering, Dalian University of Technology, Dalian, 116023, Liaoning, China.
| |
Collapse
|
24
|
WEI LINGLING, CHEN QIANG, LI ZHIYONG. STUDY ON THE IMPACT OF STRAIGHT STENTS ON ARTERIES WITH DIFFERENT CURVATURES. J MECH MED BIOL 2016. [DOI: 10.1142/s0219519416500937] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Different stent structures lead to different deformations of blood vessels, such as different cross-sectional shapes, which further influence the blood flow patterns. In this paper, six non-commercial stents with different link structures called I-, C-, S-, U-, N- and W-types were considered. Their influences on arteries with five different curvatures (i.e., 0[Formula: see text], 15[Formula: see text], 30[Formula: see text], 45[Formula: see text] and 60[Formula: see text]) were studied using finite element method. Four indices including the maximum plastic strain of stents, the rate of expansion, the maximum von Mises stress and the ellipticity of arteries, were compared for all cases. The results showed that the S-type or U-type stents, with larger plastic strain and lower von Mises stress on the arteries, provided the optimal outcome. As the link structures became complex, the arterial expansion increased monotonically, while the ellipticity of arteries showed a decreasing tendency in the vessel models. The present study could be useful for the commercial design and clinic selection of a stent with different link structures for different curved arteries.
Collapse
Affiliation(s)
- LINGLING WEI
- Biomechanics Laboratory, School of Biological Science & Medical Engineering, Southeast University, Nanjing 210096, P. R. China
| | - QIANG CHEN
- Biomechanics Laboratory, School of Biological Science & Medical Engineering, Southeast University, Nanjing 210096, P. R. China
| | - ZHIYONG LI
- Biomechanics Laboratory, School of Biological Science & Medical Engineering, Southeast University, Nanjing 210096, P. R. China
- School of Chemistry, Physics and Mechanical Engineering, Queensland University of Technology (QUT), Brisbane, QLD 4001, Australia
| |
Collapse
|
25
|
Tian X, Sun A, Liu X, Pu F, Deng X, Kang H, Fan Y. Influence of catheter insertion on the hemodynamic environment in coronary arteries. Med Eng Phys 2016; 38:946-51. [PMID: 27394085 DOI: 10.1016/j.medengphy.2016.06.013] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2016] [Revised: 04/13/2016] [Accepted: 06/08/2016] [Indexed: 11/25/2022]
Abstract
Intravascular stenting is one of the most commonly used treatments to restore the vascular lumen and flow conditions, while perioperative complications such as thrombosis and restenosis are still nagging for patients. As the catheter with crimped stent and folded balloon is directly advanced through coronary artery during surgery, it is destined to cause interference as well as obstructive effect on blood flow. We wonder how the hemodynamic environment would be disturbed and weather these disturbances cause susceptible factors for those complications. Therefore, a realistic three-dimensional model of left coronary artery was reconstructed and blood flow patterns were numerically simulated at seven different stages in the catheter insertion process. The results revealed that the wall shear stress (WSS) and velocity in left anterior descending (LAD) were both significantly increased after catheter inserted into LAD. Besides, the WSS on the catheter, especially at the ending of the catheter, was also at high level. Compared with the condition before catheter inserted, the endothelial cells of LAD was exposed to high-WSS condition and the risk of platelet aggregation in blood flow was increased. These influences may make coronary arteries more vulnerable for perioperative complications.
Collapse
Affiliation(s)
- Xiaopeng Tian
- Key Laboratory for Biomechanics and Mechanobiology of Ministry of Education, International Joint Research Center of Aerospace Biotechnology & Medical Engineering, Ministry of Science and Technology, School of Biological Science and Medical Engineering, Beihang University, 100191 Beijing, China
| | - Anqiang Sun
- Key Laboratory for Biomechanics and Mechanobiology of Ministry of Education, International Joint Research Center of Aerospace Biotechnology & Medical Engineering, Ministry of Science and Technology, School of Biological Science and Medical Engineering, Beihang University, 100191 Beijing, China.
| | - Xiao Liu
- Key Laboratory for Biomechanics and Mechanobiology of Ministry of Education, International Joint Research Center of Aerospace Biotechnology & Medical Engineering, Ministry of Science and Technology, School of Biological Science and Medical Engineering, Beihang University, 100191 Beijing, China
| | - Fang Pu
- Key Laboratory for Biomechanics and Mechanobiology of Ministry of Education, International Joint Research Center of Aerospace Biotechnology & Medical Engineering, Ministry of Science and Technology, School of Biological Science and Medical Engineering, Beihang University, 100191 Beijing, China
| | - Xiaoyan Deng
- Key Laboratory for Biomechanics and Mechanobiology of Ministry of Education, International Joint Research Center of Aerospace Biotechnology & Medical Engineering, Ministry of Science and Technology, School of Biological Science and Medical Engineering, Beihang University, 100191 Beijing, China
| | - Hongyan Kang
- Key Laboratory for Biomechanics and Mechanobiology of Ministry of Education, International Joint Research Center of Aerospace Biotechnology & Medical Engineering, Ministry of Science and Technology, School of Biological Science and Medical Engineering, Beihang University, 100191 Beijing, China
| | - Yubo Fan
- Key Laboratory for Biomechanics and Mechanobiology of Ministry of Education, International Joint Research Center of Aerospace Biotechnology & Medical Engineering, Ministry of Science and Technology, School of Biological Science and Medical Engineering, Beihang University, 100191 Beijing, China.
| |
Collapse
|
26
|
Imani SM, Goudarzi AM, Ghasemi SE, Kalani A, Mahdinejad J. Analysis of the stent expansion in a stenosed artery using finite element method: application to stent versus stent study. Proc Inst Mech Eng H 2015; 228:996-1004. [PMID: 25406228 DOI: 10.1177/0954411914556788] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
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 procedure. The main objective of this study is to reach to a model close to a real condition of coronary stent placement. Unlike most of the models proposed in the literature, all the steps of the deployment of a stent in the stenotic vessel (i.e. pressure increasing, constant load pressure and pressure decreasing) are simulated in this article to show the behavior of the stent in different stages of implantation. The results indicate that the first step of deployment, that is, pressure increasing, plays a main role in the success of stent implantation. So that, in order to compare the behavior of different types of stents, it is sufficient to compare their behavior at the end of pressure increasing step. In order to show the application of the findings in stent versus stent studies, three commercially available stents (the Palmaz-Schatz, Multi-Link and NIR stents) are modeled and their behavior is compared at the end of pressure increasing step. The effect of stent design on the restenosis rate is investigated. According to the findings, the possibility of restenosis is lower for Multi-Link and NIR stents in comparison with Palmaz-Schatz stent which is in good agreement with clinical results. Therefore, the testing methodology outlined here is proposed as a simple and economical alternative for "stent versus stent" complicated clinical trials.
Collapse
Affiliation(s)
- S Misagh Imani
- Department of Mechanical Engineering, Sari Branch, Islamic Azad University, Sari, Iran
| | - A M Goudarzi
- Department of Mechanical Engineering, Babol University of Technology, Babol, Iran
| | - S E Ghasemi
- Young Researchers and Elite Club, Qaemshahr Branch, Islamic Azad University, Qaemshahr, Iran
| | - A Kalani
- Bushehr University of Medical Sciences, Bushehr, Iran
| | - J Mahdinejad
- Department of Mechanical Engineering, Sari Branch, Islamic Azad University, Sari, Iran
| |
Collapse
|
27
|
Naceur IB, Charfi A, Bouraoui T, Elleuch K. Finite element modeling of superelastic nickel-titanium orthodontic wires. J Biomech 2015; 47:3630-8. [PMID: 25458153 DOI: 10.1016/j.jbiomech.2014.10.007] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2014] [Revised: 09/26/2014] [Accepted: 10/05/2014] [Indexed: 10/24/2022]
Abstract
Thanks to its good corrosion resistance and biocompatibility, superelastic Ni–Ti wire alloys have been successfully used in orthodontic treatment. Therefore, it is important to quantify and evaluate the level of orthodontic force applied to the bracket and teeth in order to achieve tooth movement. In this study, three dimensional finite element models with a Gibbs-potential-based-formulation and thermodynamic principles were used. The aim was to evaluate the influence of possible intraoral temperature differences on the forces exerted by NiTi orthodontic arch wires with different cross sectional shapes and sizes. The prediction made by this phenomenological model, for superelastic tensile and bending tests, shows good agreement with the experimental data. A bending test is simulated to study the force variation of an orthodontic NiTi arch wire when it loaded up to the deflection of 3 mm, for this task one half of the arch wire and the 3 adjacent brackets were modeled. The results showed that the stress required for the martensite transformation increases with the increase of cross-sectional dimensions and temperature. Associated with this increase in stress, the plateau of this transformation becomes steeper. In addition, the area of the mechanical hysteresis, measured as the difference between the forces of the upper and lower plateau, increases.
Collapse
|
28
|
Design Optimisation of Coronary Artery Stent Systems. Ann Biomed Eng 2015; 44:357-67. [DOI: 10.1007/s10439-015-1373-9] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2015] [Accepted: 06/23/2015] [Indexed: 10/23/2022]
|
29
|
Li G, Li Y, Chen G, He J, Han Y, Wang X, Kaplan DL. Silk-based biomaterials in biomedical textiles and fiber-based implants. Adv Healthc Mater 2015; 4:1134-51. [PMID: 25772248 PMCID: PMC4456268 DOI: 10.1002/adhm.201500002] [Citation(s) in RCA: 80] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2015] [Revised: 02/04/2015] [Indexed: 01/25/2023]
Abstract
Biomedical textiles and fiber-based implants (BTFIs) have been in routine clinical use to facilitate healing for nearly five decades. Amongst the variety of biomaterials used, silk-based biomaterials (SBBs) have been widely used clinically viz. sutures for centuries and are being increasingly recognized as a prospective material for biomedical textiles. The ease of processing, controllable degradability, remarkable mechanical properties and biocompatibility have prompted the use of SBBs for various BTFIs for extracorporeal implants, soft tissue repair, healthcare/hygiene products and related needs. The present Review focuses on BTFIs from the perspective of types and physical and biological properties, and this discussion is followed with an examination of the advantages and limitations of BTFIs from SBBs. The Review covers progress in surface coatings, physical and chemical modifications of SBBs for BTFIs and identifies future needs and opportunities for the further development for BTFIs using SBBs.
Collapse
Affiliation(s)
- Gang Li
- National Engineering Laboratory for Modern Silk, College of Textile and Clothing Engineering, Soochow University, Suzhou 215123, P.R. China
| | - Yi Li
- Institute of Textiles and Clothing, The Hong Kong Polytechnic University, Hong Kong, China
| | - Guoqiang Chen
- National Engineering Laboratory for Modern Silk, College of Textile and Clothing Engineering, Soochow University, Suzhou 215123, P.R. China
| | - Jihuan He
- National Engineering Laboratory for Modern Silk, College of Textile and Clothing Engineering, Soochow University, Suzhou 215123, P.R. China
| | - Yifan Han
- Department of Applied Biology and Chemical Technology, The Hong Kong Polytechnic University, Hong Kong, China
| | - Xiaoqin Wang
- National Engineering Laboratory for Modern Silk, College of Textile and Clothing Engineering, Soochow University, Suzhou 215123, P.R. China
| | - David L. Kaplan
- Department of Biomedical Engineering, Tufts University, 4 Colby St, Room 153, Medford, MA 02155, USA
| |
Collapse
|
30
|
Bae IH, Lim KS, Park JK, Park DS, Lee SY, Jang EJ, Ji MS, Sim DS, Hong YJ, Ahn Y, Park JC, Cho JG, Kang JC, Kim IS, Nah JW, Jeong MH. Mechanical behavior and in vivo properties of newly designed bare metal stent for enhanced flexibility. J IND ENG CHEM 2015. [DOI: 10.1016/j.jiec.2014.05.045] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
|
31
|
McGrath D, O׳Brien B, Bruzzi M, McHugh P. Nitinol stent design – understanding axial buckling. J Mech Behav Biomed Mater 2014; 40:252-263. [DOI: 10.1016/j.jmbbm.2014.08.029] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2014] [Revised: 08/28/2014] [Accepted: 08/31/2014] [Indexed: 11/25/2022]
|
32
|
Analyses and design of expansion mechanisms of balloon expandable vascular stents. J Biomech 2014; 47:1438-46. [DOI: 10.1016/j.jbiomech.2014.01.039] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2012] [Revised: 01/16/2014] [Accepted: 01/18/2014] [Indexed: 11/24/2022]
|
33
|
Paryab N, Cronin DS, Lee-Sullivan P. Finite element methods to analyze helical stent expansion. INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN BIOMEDICAL ENGINEERING 2014; 30:339-352. [PMID: 24123985 DOI: 10.1002/cnm.2605] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/15/2013] [Revised: 08/23/2013] [Accepted: 09/17/2013] [Indexed: 06/02/2023]
Abstract
Helical polymeric stents have been proposed as a suitable geometry for biodegradable drug-eluting polymer-based stents. However, helical stents often experience nonuniform local expansion (dog boning), which can prohibit full stent expansion using conventional methods. The development of stents and deployment methods is challenging and can be supported by numerical analysis; however, this complex problem is often approached with simplified boundary conditions that may not be appropriate for helical stents. The finite element method (explicit and implicit) was used to investigate three common stent expansion approaches with a focus on helical stent geometry, which differs from traditional wire mesh stent expansion. Although each of the three methods considered provided some insight into the expansion characteristics, common displacement controlled, and uniform expansion methods were not able to demonstrate the characteristic local deformations observed in expansion. A coupled stent-balloon model, although computationally expensive, was able to demonstrate the expected nonuniform deformation. To address nonuniform expansion, a progressive expansion approach has been investigated and verified numerically. This method may also provide a suitable solution for nonuniform expansion in other stent designs by minimizing loading and potential damage to the artery that can occur during stent deployment.
Collapse
Affiliation(s)
- Nasim Paryab
- University of Waterloo, Waterloo, Ontario, Canada
| | | | | |
Collapse
|
34
|
Zhang LT. Modeling of Soft Tissues Interacting with Fluid (Blood or Air) Using the Immersed Finite Element Method. JOURNAL OF BIOMEDICAL SCIENCE AND ENGINEERING 2014; 7:130-145. [PMID: 26855688 PMCID: PMC4743898 DOI: 10.4236/jbise.2014.73018] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
This paper presents some biomedical applications that involve fluid-structure interactions which are simulated using the Immersed Finite Element Method (IFEM). Here, we first review the original and enhanced IFEM methods that are suitable to model incompressible or compressible fluid that can have densities that are significantly lower than the solid, such as air. Then, three biomedical applications are studied using the IFEM. Each of the applications may require a specific set of IFEM formulation for its respective numerical stability and accuracy due to the disparities between the fluid and the solid. We show that these biomedical applications require a fully-coupled and stable numerical technique in order to produce meaningful results.
Collapse
Affiliation(s)
- Lucy T. Zhang
- JEC 2049, Department of Mechanical, Aerospace, and Nuclear Engineering, Troy, USA
| |
Collapse
|
35
|
Design optimization of coronary stent based on finite element models. ScientificWorldJournal 2013; 2013:630243. [PMID: 24222743 PMCID: PMC3814053 DOI: 10.1155/2013/630243] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2013] [Accepted: 09/02/2013] [Indexed: 11/28/2022] Open
Abstract
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. An infilling sampling criterion named expected improvement (EI) is used to balance local and global searches in the optimization iteration. Four commonly used finite element models of stent dilation were used to investigate stent dogboning rate. Thrombosis models of three typical shapes are built to test the effectiveness of optimization results. Numerical results show that two finite element models dilated by pressure applied inside the balloon are available, one of which with the artery and plaque can give an optimal stent with better expansion behavior, while the artery and plaque unincluded model is more efficient and takes a smaller amount of computation.
Collapse
|
36
|
Martin D, Boyle F. Finite element analysis of balloon-expandable coronary stent deployment: influence of angioplasty balloon configuration. INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN BIOMEDICAL ENGINEERING 2013; 29:1161-1175. [PMID: 23696255 DOI: 10.1002/cnm.2557] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/24/2012] [Revised: 03/09/2013] [Accepted: 04/12/2013] [Indexed: 06/02/2023]
Abstract
Today, the majority of coronary stents are balloon-expandable and are deployed using a balloon-tipped catheter. To improve deliverability, the membrane of the angioplasty balloon is typically folded about the catheter in a pleated configuration. As such, the deployment of the angioplasty balloon is governed by the material properties of the balloon membrane, its folded configuration and its attachment to the catheter. Despite this observation, however, an optimum strategy for modelling the configuration of the angioplasty balloon in finite element studies of coronary stent deployment has not been identified, and idealised models of the angioplasty balloon are commonly employed in the literature. These idealised models often neglect complex geometrical features, such as the folded configuration of the balloon membrane and its attachment to the catheter, which may have a significant influence on the deployment of a stent. In this study, three increasingly sophisticated models of a typical semi-compliant angioplasty balloon were employed to determine the influence of angioplasty balloon configuration on the deployment of a stent. The results of this study indicate that angioplasty balloon configuration has a significant influence on both the transient behaviour of the stent and its impact on the mechanical environment of the coronary artery.
Collapse
Affiliation(s)
- David Martin
- Department of Mechanical Engineering, Dublin Institute of Technology, Ireland
| | | |
Collapse
|
37
|
Kim DB, Choi H, Joo SM, Kim HK, Shin JH, Hwang MH, Choi J, Kim DG, Lee KH, Lim CH, Yoo SK, Lee HM, Sun K. A Comparative Reliability and Performance Study of Different Stent Designs in Terms of Mechanical Properties: Foreshortening, Recoil, Radial Force, and Flexibility. Artif Organs 2013; 37:368-79. [DOI: 10.1111/aor.12001] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Affiliation(s)
- Dong Bin Kim
- Graduate Program in Biomedical Engineering; Yonsei University
| | - Hyuk Choi
- Department of Advanced Materials Science and Engineering; Kangwon National University
| | - Sang Min Joo
- Department of Mechanical Engineering; Sogang University
| | - Han Ki Kim
- Department of Mechanical Engineering; Dankook University
| | - Jae Hee Shin
- Department of Advanced Materials Science and Engineering; Kangwon National University
| | - Min Ho Hwang
- Department of Advanced Materials Science and Engineering; Kangwon National University
| | - Jaesoon Choi
- Asan Institute of Life Sciences; Asan Medical Center and University of Ulsan College of Medicine
| | - Dong-Gon Kim
- Department of Polymer Engineering; Sunchon University
| | - Kwang Ho Lee
- Department of Medical Sciences; Graduate School of Medicine; Korea University; Seoul; Korea
| | - Chun Hak Lim
- Department of Anesthesiology and Pain Medicine; College of Medicine; Korea University; Seoul; Korea
| | - Sun Kook Yoo
- Graduate Program in Biomedical Engineering; Yonsei University
| | - Heung-Man Lee
- Department of Otorhinolaryngology-Head and Neck Surgery; College of Medicine; Korea University; Seoul; Korea
| | - Kyung Sun
- Department of Thoracic and Cardiovascular Surgery; College of Medicine; Korea University; Seoul; Korea
| |
Collapse
|
38
|
Zhao S, Gu L, Froemming SR. On the Importance of Modeling Stent Procedure for Predicting Arterial Mechanics. J Biomech Eng 2012; 134:121005. [DOI: 10.1115/1.4023094] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
The stent-artery interactions have been increasingly studied using the finite element method for better understanding of the biomechanical environment changes on the artery and its implications. However, the deployment of balloon-expandable stents was generally simplified without considering the balloon-stent interactions, the initial crimping process of the stent, its overexpansion routinely used in the clinical practice, or its recoil process. In this work, the stenting procedure was mimicked by incorporating all the above-mentioned simplifications. The impact of various simplifications on the stent-induced arterial stresses was systematically investigated. The plastic strain history of stent and its resulted geometrical variations, as well as arterial mechanics were quantified and compared. Results showed the model without considering the stent crimping process underestimating the minimum stent diameter by 17.2%, and overestimating the maximum radial recoil by 144%. It was also suggested that overexpansion resulted in a larger stent diameter, but a greater radial recoil ratio and larger intimal area with high stress were also obtained along with the increase in degree of overexpansion.
Collapse
Affiliation(s)
- Shijia Zhao
- Department of Mechanical and Materials Engineering, University of Nebraska-Lincoln, Lincoln, NE 68588-0656
| | - Linxia Gu
- Department of Mechanical and Materials Engineering, University of Nebraska-Lincoln, Lincoln, NE 68588-0656 Nebraska Center for Materials and Nanoscience, Lincoln, NE 68588-0656 e-mail:
| | - Stacey R. Froemming
- Hybrid Catheterization and Electrophysiology Laboratory, Children's Hospital and Medical Center, Omaha, NE 68114-4133
| |
Collapse
|
39
|
In vitro haematic proteins adsorption and cytocompatibility study on acrylic copolymer to realise coatings for drug-eluting stents. MATERIALS SCIENCE & ENGINEERING. C, MATERIALS FOR BIOLOGICAL APPLICATIONS 2012. [DOI: 10.1016/j.msec.2012.07.020] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
|
40
|
|
41
|
Hsiao HM, Chiu YH, Wu TY, Shen JK, Lee TY. Effects of through-hole drug reservoirs on key clinical attributes for drug-eluting depot stent. Med Eng Phys 2012; 35:884-97. [PMID: 22995147 DOI: 10.1016/j.medengphy.2012.08.021] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2011] [Revised: 08/24/2012] [Accepted: 08/28/2012] [Indexed: 10/27/2022]
Abstract
Atherosclerosis, a condition related to cholesterol build-up and thickening of the inner wall of the artery, narrows or occludes the artery lumen. The drug-eluting stent is a major breakthrough for the treatment of such coronary artery diseases. In recent years, another innovative variation of the drug-eluting stent with drug reservoirs has been introduced. It allows programmable drug delivery with spatial and temporal control and has several potential advantages over traditional drug-eluting stents. However, creating such reservoirs on the stent struts may weaken the stent scaffolding and compromise its mechanical integrity. In this paper, the effects of these micro-sized through-hole drug reservoirs on several key clinically relevant functional attributes of the depot stent were investigated. Finite element models were developed to predict the mechanical integrity of a balloon-expandable stent at various stages such as manufacturing and deployment, as well as the stent radial strength and fatigue life. Results show that (1) creating drug reservoirs on a stent could impact the stent fatigue resistance to some degree; (2) drug reservoirs on the stent crowns led to much greater loss in all key clinical attributes than reservoirs on other locations; (3) reservoir shape change resulted in little differences in all key clinical attributes; (4) for the same drug loading capacity, larger and fewer reservoirs yielded lower equivalent plastic strain and radial strength but higher fatigue safety factor; and (5) the proposed depot stent was proven to be a feasible design. Its total drug capacity could be tripled with acceptable marginal trade-off in key clinical attributes. These results can serve as the guidelines to help future stent designs to achieve the best combination of stent mechanical integrity and smart drug delivery in the future, thereby opening up a wide variety of new treatment potentials and opportunities.
Collapse
Affiliation(s)
- Hao-Ming Hsiao
- Department of Mechanical Engineering, National Taiwan University, Taipei, Taiwan.
| | | | | | | | | |
Collapse
|
42
|
Barrera O, Makradi A, Abbadi M, Azaouzi M, Belouettar S. On high-cycle fatigue of 316L stents. Comput Methods Biomech Biomed Engin 2012; 17:239-50. [DOI: 10.1080/10255842.2012.677442] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
|
43
|
Paryab N, Cronin D, Lee-Sullivan P, Ying X, Boey FYC, Venkatraman S. Uniform Expansion of a Polymeric Helical Stent. J Med Device 2012. [DOI: 10.1115/1.4005777] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
Helical coil polymeric stents provide an alternative method of stenting compared to traditional metallic stents, but require additional investigation to understand deployment, expansion, and fixation. A bilayer helical coil stent consisting of PLLA and PLGA was investigated using the finite element model to evaluate performance by uniform expansion and subsequent recoiling. In vitro material characterization studies showed that a preinsertion water-soaking step to mimic body implantation conditions provided the required ductility level expansion. In this case, the mechanical contribution of the outer PLGA layer was negligible since it softened significantly under environmental conditions. The viscoelastic response was not considered in this study since the strain rate during expansion was relatively slow and the material response was primarily plastic. The numerical model was validated with available experimental expansion and recoiling data. A parametric study was then undertaken to investigate the effect of stent geometry and coefficient of friction at the stent-cylinder interface on the expansion and recoiling characteristics. The model showed that helical stents exhibit a uniform stress distribution after expansion, which is important for controlled degradation when using biodegradable materials. The results indicated that increasing stent width, pitch value, and coil thickness resulted in a larger diameter after recoiling, which would improve fixation in the artery. It was also noted that a helical stent should have more than five coils to be stable after recoiling. This work is part of a larger research study focused on the performance of a balloon-inflated polymeric helical stent for artery applications.
Collapse
Affiliation(s)
- Nasim Paryab
- Department of Mechanical and Mechatronics Engineering, University of Waterloo, 200 University Avenue West Waterloo, Ontario N2L 3G1, Canada
| | - Duane Cronin
- Department of Mechanical and Mechatronics Engineering, University of Waterloo, 200 University Avenue West Waterloo, Ontario N2L 3G1, Canada
| | - Pearl Lee-Sullivan
- Department of Mechanical and Mechatronics Engineering, University of Waterloo, 200 University Avenue West Waterloo, Ontario N2L 3G1, Canada
| | - Xiong Ying
- Nanyang Technological University, Nanyang Avenue, Singapore 639798, Singapore
| | - Freddy Y. C. Boey
- Nanyang Technological University, Nanyang Avenue, Singapore 639798, Singapore
| | - Subbu Venkatraman
- Nanyang Technological University, Nanyang Avenue, Singapore 639798, Singapore
| |
Collapse
|
44
|
Hsiao HM, Chiu YH. Assessment of mechanical integrity for drug-eluting renal stent with micro-sized drug reservoirs. Comput Methods Biomech Biomed Engin 2012; 16:1307-18. [PMID: 22436070 DOI: 10.1080/10255842.2012.670851] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Abstract
The drug-eluting stent (DES) has become the gold standard worldwide for the treatment of cardiovascular diseases. In recent years, an innovative variation of the DES with micro-sized drug reservoirs has been introduced. It allows programmable drug delivery with both spatial and temporal control and has several potential advantages over traditional DESs. However, creating such reservoirs on the stent struts may weaken the structure of the stent scaffolding and compromise its mechanical integrity. In this study, we propose to use this innovative stent concept in the renal indication for potential treatment of both renal artery stenosis (upstream) and its associated kidney diseases (downstream) at the same time. The effects of these micro-sized drug reservoirs on several key clinically relevant functional attributes of the drug-eluting renal stent were systematically and quantitatively investigated. Finite element models were developed to predict the mechanical integrity of a balloon-expandable stent at various stages. Results show that (1) creating drug reservoirs on a stent could impact the stent fatigue resistance to certain degrees; (2) drug reservoirs on the stent crowns lead to greater loss in all key stent attributes than reservoirs on either bar arms or connectors and (3) the proposed optimised depot stent was proven to be feasible and could triple drug capacity than the current DESs, with marginal trade-off in its key clinical attributes. These results can serve as the guidelines to help future stent designs to achieve the best combination of stent structural integrity and smart drug delivery in the future.
Collapse
Affiliation(s)
- Hao-Ming Hsiao
- a Department of Mechanical Engineering , National Taiwan University , Taipei , Taiwan
| | | |
Collapse
|
45
|
Martin D, Boyle FJ. Computational structural modelling of coronary stent deployment: a review. Comput Methods Biomech Biomed Engin 2011; 14:331-48. [DOI: 10.1080/10255841003766845] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
|
46
|
Gagliardi M. Relevance of Mesh Dimension Optimization, Geometry Simplification and Discretization Accuracy in the Study of Mechanical Behaviour of Bare Metal Stents. ACTA ACUST UNITED AC 2010. [DOI: 10.4018/jcmam.2010100103] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
In this paper, a set of analyses on the deployment of coronary stents by using a nonlinear finite element method is proposed. The author proposes a convergence test able to select the appropriate mesh dimension and a methodology to perform the simplification of structures composed of cyclically repeated units to reduce the number of degree of freedom and the analysis run time. A systematic study, based on the analysis of seven meshes for each model, is performed, gradually reducing the element dimension. In addition, geometric models are simplified considering symmetries; adequate boundary conditions are applied and verified based on the results obtained from analysis of the whole model.
Collapse
|
47
|
Simulation of a balloon expandable stent in a realistic coronary artery—Determination of the optimum modelling strategy. J Biomech 2010; 43:2126-32. [DOI: 10.1016/j.jbiomech.2010.03.050] [Citation(s) in RCA: 95] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2010] [Revised: 03/26/2010] [Accepted: 03/31/2010] [Indexed: 11/23/2022]
|
48
|
Li J, Luo Q, Xie Z, Li Y, Zeng Y. Fatigue life analysis and experimental verification of coronary stent. Heart Vessels 2010; 25:333-7. [PMID: 20676843 DOI: 10.1007/s00380-009-1203-9] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/02/2009] [Accepted: 09/11/2009] [Indexed: 11/25/2022]
Abstract
A computational and experimental method on biomechanics of stent is presented to analyze the stress distribution of different phases and evaluate the fatigue life according to Goodman criteria. As a result, the maximum stress and alternating stress were always located at the curvature area of rings, the fatigue bands in the experiment also verified the computation rationality. Matching between the numerical simulation and experimental results was satisfactory, which proved that the finite element analysis could provide theoretical evidence and help design and optimize the stent structure.
Collapse
Affiliation(s)
- Jianjun Li
- MicroPort Medical (Shanghai) Co. Ltd, Shanghai 201203, PR China
| | | | | | | | | |
Collapse
|
49
|
Yang J, Liang MB, Huang N, Liu YL. Studying the non-uniform expansion of a stent influenced by the balloon. J Med Eng Technol 2010; 34:301-5. [DOI: 10.3109/03091902.2010.481031] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
|
50
|
O'Connell BM, McGloughlin TM, Walsh MT. Factors that affect mass transport from drug eluting stents into the artery wall. Biomed Eng Online 2010; 9:15. [PMID: 20214774 PMCID: PMC2854105 DOI: 10.1186/1475-925x-9-15] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2009] [Accepted: 03/09/2010] [Indexed: 01/12/2023] Open
Abstract
Coronary artery disease can be treated by implanting a stent into the blocked region of an artery, thus enabling blood perfusion to distal vessels. Minimally invasive procedures of this nature often result in damage to the arterial tissue culminating in the re-blocking of the vessel. In an effort to alleviate this phenomenon, known as restenosis, drug eluting stents were developed. They are similar in composition to a bare metal stent but encompass a coating with therapeutic agents designed to reduce the overly aggressive healing response that contributes to restenosis. There are many variables that can influence the effectiveness of these therapeutic drugs being transported from the stent coating to and within the artery wall, many of which have been analysed and documented by researchers. However, the physical deformation of the artery substructure due to stent expansion, and its influence on a drugs ability to diffuse evenly within the artery wall have been lacking in published work to date. The paper highlights previous approaches adopted by researchers and proposes the addition of porous artery wall deformation to increase model accuracy.
Collapse
Affiliation(s)
- Barry M O'Connell
- Centre for Applied Biomedical Engineering Research, Department of Mechanical and Aeronautical Engineering and the Materials and Surface Science Institute, University of Limerick, Limerick, Ireland
| | | | | |
Collapse
|