Effect of Thickness on the Mechanical Properties of Magnesium Alloy Stent

2011 ◽  
Vol 383-390 ◽  
pp. 3192-3196
Author(s):  
Muhammad Iqbal Sabir ◽  
Er Bao Liu ◽  
Zhen Li ◽  
Yu Feng Zheng ◽  
Li Li
Keyword(s):  
Mechanical Properties ◽  
Coronary Stent ◽  
Stent Design ◽  
Elastic Recoil ◽  
Stent Deployment ◽  
Stent Expansion ◽  
Element Simulation ◽  
Biodegradable Stents ◽  
Nonlinear Transient

Magnesium stands for a very attractive material for biodegradable stents because of its natural process and its steady disintegration into the human body by a corrosion process. The objective of the present work is to investigate the effect of the thickness on mechanical properties of the magnesium stent design. A nonlinear transient finite element simulation has been performed to analyze the influence of various thicknesses (from 50µm to 110µm with the increment of 30µm) on the behavior of a magnesium coronary stent. The model was constrained symmetrically to ensure that any virtual rigid movement does not occur during the process of coronary stent expansion. The transient load is applied in three steps in the inner surface of the stent. Four mechanical properties are studied by mathematical modeling with determination of: (1) stent deployment pressure; (2) the intrinsic elastic recoil of the material used; (3) the stent longitudinal recoil; (4) and the stress maps. The results indicate the potential application of magnesium stent and the effect of the thickness on the behavior of magnesium stent design and material.

scholarly journals Impact of Geometry Effects on Artery Stent Deployment Characteristics

2019 ◽  
Vol 9 (2) ◽  
pp. 2029-2035
Keyword(s):  
Heart Diseases ◽  
Research Work ◽  
Computational Method ◽  
Design Parameters ◽  
Stent Design ◽  
Elastic Recoil ◽  
Stent Deployment ◽  
Strut Thickness ◽  
Maximum Expansion

Intravascular stenting is the leading treatment procedure for atherosclerotic coronary heart diseases. Among the various procedures, it is simpler and faster with a high initial success rate. Stent design, stent material, and clinical procedure decide the efficacy and life of stents. Strut thickness and crown radius are two essential design parameters that dictate expansion characteristics of stents. This research work discusses computational analysis of a specific stent, to explore the influence of thickness of strut on the deployment characteristics like stress/strain, foreshortening, recoil, and dog boning. The optimum stent design is one which gives maximum expansion with minimum stress distribution, dogboning, and elastic recoil. Five similar stent models with thickness ranges from 65μ to 105µ were modeled and computational method was adopted to simulate the transitory expansion nature of stent/balloon system. The FE results were substantiated with an in-vitro experiment. It was found that strut thickness has a major impact on stent recoil and low impact on foreshortening and dogboning. Foreshortening per unit expansion was almost same for entire models. Strut thickness 70μ to 80μ gives better expansion characteristics for the model under study.

scholarly journals Magnesium Alloy Stent Expansion Behavior Simulated by Finite Element Method

2012 ◽  
Vol 232 ◽  
pp. 697-700
Author(s):  
Muhammad Iqbal Sabir ◽  
Er Bao Liu ◽  
Zhen Li ◽  
Yu Feng Zheng ◽  
Li Li
Keyword(s):  
Finite Element ◽  
Magnesium Alloy ◽  
Element Model ◽  
Elastic Recoil ◽  
Stent Deployment ◽  
Coverage Area ◽  
Cross Sectional ◽  
Stent Expansion ◽  
Area 5 ◽  
Stent Coverage

Biodegradable magnesium alloy stents have gained increasing interest in the past years due to their potential prospect. Magnesium alloy is brittle compared with stainless steel. This means it has less elongation than other stent materials and it may cause strut break under large deformation. In this paper, a finite element model for magnesium alloy stent is studied to simulate the mechanical behavior of the stent. It is composed of 1.5mm in inner diameter, 7mm length, 80µm thickness and 110µm in cross-sectional width. Six mechanical properties have been studied by mathematical modeling with determination of: (1) stent deployment pressure; (2) the intrinsic elastic recoil of the material used; (3) the stent foreshortening; (4) the stent coverage area, (5) the stent flexibility; and (6) the stress maps.

Effect of Photoactivated Cross-Linking Compound on Mechanical Properties of Porcine Carotid Arteries Post-Angioplasty

2019 ◽  
Author(s):  
Farshad Mogharrabi ◽  
Jonathan Kuhlenhoelter ◽  
Blake Anderson ◽  
Katalin Kauser ◽  
Kenneth Monson
Keyword(s):  
Mechanical Properties ◽  
Transluminal Angioplasty ◽  
Elastic Behavior ◽  
Cross Linking ◽  
Medical Procedure ◽  
Elastic Recoil ◽  
Stent Deployment ◽  
Arterial Lumen ◽  
Post Surgery ◽  
Severe Atherosclerosis

Abstract Percutaneous transluminal angioplasty (PTA) is a medical procedure performed on patients with severe atherosclerosis to open up stenosed blood vessels by inflating a balloon at the narrowing location. In many cases of PTA, restenosis occurs post-surgery due either to elastic behavior of the artery, also known as elastic recoil in medical literature, or to plaque reformation within the lumen. For that reason, stents are commonly deployed to keep the arterial lumen open. Stent deployment causes problems in some cases; for example, the presence of stents in arteries with frequent movements and large deformations can cause ruptures in the arterial wall. Recent studies on 1,8-Naphthalimide organic compounds have shown that when these compounds are activated using a certain wavelength of light, it causes cross-linking between the components of the extracellular matrix. This observation has led to studies with the goal of developing a method to utilize this process to replace stents for cases with limiting conditions for stent deployment. In this study we focused on measuring and quantifying the effects of this compound on the mechanical properties of treated arteries undergoing PTA under a variety of loading conditions.

Determination of adequate coronary stent expansion using StentBoost, a novel fluoroscopic image processing technique

2006 ◽  
Vol 69 (1) ◽  
pp. 84-93 ◽  
Author(s):  
Jacob M. Mishell ◽  
Kalpesh T. Vakharia ◽  
Thomas A. Ports ◽  
Yerem Yeghiazarians ◽  
Andrew D. Michaels
Keyword(s):  
Image Processing ◽  
Processing Technique ◽  
Coronary Stent ◽  
Image Processing Technique ◽  
Fluoroscopic Image ◽  
Stent Expansion

Basic set of experiments for determination of mechanical properties of sand

2014 ◽  
Vol 62 (1) ◽  
pp. 129-137
Author(s):  
A. Sawicki ◽  
J. Mierczyński
Keyword(s):  
Mechanical Properties ◽  
Soil Mechanics ◽  
Physical And Mechanical Properties ◽  
Local Strain ◽  
Initial State ◽  
Laboratory Equipment ◽  
Additional Information ◽  
Basic Set ◽  
Initial Anisotropy

Abstract A basic set of experiments for the determination of mechanical properties of sands is described. This includes the determination of basic physical and mechanical properties, as conventionally applied in soil mechanics, as well as some additional experiments, which provide further information on mechanical properties of granular soils. These additional experiments allow for determination of steady state and instability lines, stress-strain relations for isotropic loading and pure shearing, and simple cyclic shearing tests. Unconventional oedometric experiments are also presented. Necessary laboratory equipment is described, which includes a triaxial apparatus equipped with local strain gauges, an oedometer capable of measuring lateral stresses and a simple cyclic shearing apparatus. The above experiments provide additional information on soil’s properties, which is useful in studying the following phenomena: pre-failure deformations of sand including cyclic loading compaction, pore-pressure generation and liquefaction, both static and caused by cyclic loadings, the effect of sand initial anisotropy and various instabilities. An important feature of the experiments described is that they make it possible to determine the initial state of sand, defined as either contractive or dilative. Experimental results for the “Gdynia” model sand are shown.

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