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Finite element methods to analyze helical stent expansion
Author(s) -
Paryab Nasim,
Cronin Duane S.,
LeeSullivan Pearl
Publication year - 2014
Publication title -
international journal for numerical methods in biomedical engineering
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.741
H-Index - 63
eISSN - 2040-7947
pISSN - 2040-7939
DOI - 10.1002/cnm.2605
Subject(s) - stent , finite element method , structural engineering , displacement (psychology) , computer science , expansion ratio , boundary value problem , material properties , materials science , geometry , mechanics , mathematics , mathematical analysis , physics , engineering , composite material , surgery , medicine , psychotherapist , psychology
SUMMARY 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. Copyright © 2013 John Wiley & Sons, Ltd.