Abstract The high mortality of atherosclerosis-caused cardiovascular disease has promoted the requirement of designing novel intravascular stents with comprehensive robust mechanical performances, which is critical for re-constructing the blocked artery and recovering the biomechanical functions of artery vessels during vascular interventional therapy procedures. In this study, a chiral constrained structure with zero/negative Poisson's ratio and robust expansion transformation ability is proposed through combining the axial constraint effect of tetrachiral element and the good stretchability of oscillating wave element along circumferential direction. Afterwards, through applying the theoretical prediction, experimental tests and finite element analysis, the mechanical properties and stenting performances of the chiral constrained structure are explored. The modified tetrachiral topology shows strong orthotropic after integration of oscillating wave strut profile, indicating its capability of handling radial loads without great longitudinal recoil (foreshortening). Finally, stent deployment performances have been evaluated through a highly nonlinear coupling analysis of the stenosed vessels system, in terms of transformation characteristics, dogboning, radial recoil, foreshortening, and plaque prolapse ratio, etc. Especially, remarkable non-conventional performances of anti-dogboning and anti-foreshortening are identified in chiral constrained stent. Synthetically index is generated to compensate the competing behaviors among the above terms, and to improve the comprehensive mechanical performances of chiral constrained stent. These results show the potential in generating a new family of the intravascular stent with chiral mechanical metamaterials and provide a promising clinical application in curing atherosclerosis.

中文翻译：

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手性约束支架：结构设计对机械和血管内支架部署性能的影响

摘要 动脉粥样硬化引起的心血管疾病的高死亡率促进了设计具有综合稳健机械性能的新型血管支架的需求，这对于血管介入治疗过程中重建阻塞的动脉和恢复动脉血管的生物力学功能至关重要。本研究结合四手性元件的轴向约束作用和振荡波元件沿圆周方向的良好拉伸性，提出了一种零/负泊松比和鲁棒膨胀变换能力的手性约束结构。之后，通过应用理论预测、实验测试和有限元分析，探索了手性约束结构的力学性能和支架性能。改进的四手性拓扑结构在整合振荡波支柱轮廓后显示出很强的正交各向异性，表明其能够处理径向载荷而没有很大的纵向后坐力（缩短）。最后，通过对狭窄血管系统的高度非线性耦合分析，评估了支架部署性能，包括转换特性、狗骨、径向回缩、缩短和斑块脱垂率等。在手性约束支架中发现了dogboning 和anti-foreshortening。生成综合索引以补偿上述项之间的竞争行为，并提高手性受限支架的综合力学性能。这些结果显示了使用手性机械超材料产生新的血管内支架家族的潜力，并为治疗动脉粥样硬化提供了有希望的临床应用。