Annu Int Conf IEEE Eng Med Biol Soc. 2021 Nov;2021:4324-4328. doi: 10.1109/EMBC46164.2021.9630612.
Drug-Eluting Stents (DES) are commonly used in coronary angioplasty operations as a solution against artery stenosis and restenosis. Computational Bioengineering allows for the in-silico analysis of their performance. The scope of this work is to develop a DES Digital Twin, focusing on the mechanical integrity of its biodegradable coating throughout the operational lifecycle. The implementation leverages the Finite Element Method (FEM) to compute the developed mechanical stress field on the DES during the inflation/deflation stage, followed by the degradation of the polymer-based coating. The simulation of the degradation process is based on a Continuum Damage Mechanics (CDM) model that considers bulk degradation. The CDM algorithm is implemented on the NX Nastran solver through a user-defined material (UMAT) subroutine. For benchmarking purposes and to compare with the baseline design of the BioCoStent project, this conceptual study implements an alternative stent design, to study the effect of the geometry on the developed stresses. Additionally, the effect of the degradation rate on the polymer-based coating's lifecycle is studied via sensitivity analysis.
药物洗脱支架（DES）常用于经皮冠状动脉介入治疗，以对抗动脉狭窄和再狭窄。计算生物工程允许对其性能进行计算机模拟分析。这项工作的范围是开发一个 DES 的数字孪生体，重点是其生物可降解涂层在整个运行生命周期内的机械完整性。该实现利用有限元方法（FEM）来计算在膨胀/收缩阶段 DES 上的机械应力场，然后是聚合物基涂层的降解。降解过程的模拟基于考虑整体降解的连续损伤力学（CDM）模型。CDM 算法通过用户定义的材料（UMAT）子程序在 NX Nastran 求解器上实现。为了进行基准测试并与 BioCoStent 项目的基线设计进行比较，本概念研究实施了一种替代支架设计，以研究几何形状对所开发的应力的影响。此外，通过敏感性分析研究了降解速率对聚合物基涂层生命周期的影响。
