可吸收支架生物力学性能分析

分析和评估可降解支架在加工和临床使用时的生物力学性能。基于有限元方法,建立六面体网格模型,假设支架和模拟血管为各向同性的不可压缩材料,分别赋予弹塑性和超弹性本构模型,根据加工和临床情况施加边界条件和接触条件,使用有限元软件ABAQUS的隐式求解器,模拟3种规格支架B-2508、B-3018和B-3528在压握、扩张、后扩张和疲劳工况下的表现。结果表明,压握时,这3种支架的应力峰值分别为55.47、55.47 和50.51 MPa;扩张时,这3种支架的应力峰值分别为64.10、66.09和66.25 MPa;后扩张时,这3种支架的应力峰值为66.10、65.85和67.85 MPa。在疲劳图中,B-2508和B-3018的平均应力交变应力坐标均位于疲劳临界线1以下,而B-3528中少数节点的坐标位于疲劳临界线1以上。总的来说,压握安全性方面,B-3528最优;扩张安全性方面,B-2508最优;疲劳安全性方面,B-3018最优。研究结果对可吸收支架提供一种准确的生物力学性能模拟分析方法,为可吸收支架类的产品开发和临床精确操作提供理论指导。

Biomechanical Analysis for Bioabsorbable Scaffolds

The purpose of the research is to analyze and evaluate the biomechanical capability of bioabsorbable scaffolds during processing and clinical application. Based onfinite element method, hexahedron mesh models were generated. Scaffolds and mock vessels were assumed to be isotropic incompressible materials, with constitutive models of elastoplasticity and hyperelasticity, respectively. Boundary and contact conditions were applied in the basis of practical processing and clinical applications. The Implicit solver of finite element software Abaqus were utilized to simulate the performance of three specific bioabsorbable scaffolds,B-2508, B-3018, and B-3528, under loadings for crimping, dilation, post-dilation and fatigue. The results were demonstrated. During crimping, the peak stress values for scaffold B-2508, B-3018, and B-3528 were 55.47, 55.47, and 50.51 MPa respectively. During dilation, the peak stress values were 64.10, 66.09, and 66.25 MPa respectively. During post-dilation, the peak stress values were 66.10, 65.85, and 67.85 MPa respectively. In high-cycle fatigue graph, all coordinates of mean stress-alternate stress for B-2508 and B-3018 were below the fatigue-critical line 1, while coordinates of a few nodes for B-3528 were above the fatigue-critical line 1. In summary, B-3528 was the best for crimping safety, B-2508 was the best for dilation safety, and B-3018 was the best for fatigue safety. Based on this study, an accurate simulation analytical method of biomechanical capability for bioabsorbable scaffolds were provided, and a theoretical instruction were conducted for product development of bioabsorbable-scaffold-like devices and precise clinical operations.