用于治疗法洛四联症的肺瓣支架有限元评估-《中国医学物理学杂志》

文章信息/Info

Title:: Evaluation?f?ulmonary?alve?tents?or?he?reatment?f?etralogy?f?allot?ased?n?inite element method

作者:: 贾云超1; 曾赣鹤1; 陈思1; 荆腾1; 贺照明1; 2; 1.江苏大学流体机械工程技术研究中心生物医学工程系，江苏镇江 212013； 2.德州理工大学机械工程系，美国德克萨斯州拉伯克 79409

Author(s):: JIA Yunchao1; ZENG Ganhe1; CHEN Si1; JING Teng1; HE Zhaoming1; 2; 1. Department of Biomedical Engineering, Research Center of Fluid Machinery Engineering and Technology, Jiangsu University, Zhenjiang 212013, China 2. Department of Mechanical Engineering, Texas Tech University, Lubbock 79409, USA

Keywords:: Keywords: tetralogy of Fallot pulmonary valve stent balloon dilation plastic deformation finite element analysis

摘要:: 目的：分析所提出的用于治疗法洛四联症的肺动脉瓣支架在球囊扩张和卸载后的力学行为以评估可行性。方法：应用有限元方法，设计了两类网格连接构型（“X”型和“H”型）的肺动脉瓣支架，对球囊扩张支架过程和撤去球囊回缩过程进行模拟，评估应力、等效塑性应变、扩张量，分析支架网格连接方式不同产生的影响。结果：最大应力和塑性应变出现在网格交接处，但没有超过强度极限，“H”型支架比“X”型支架表现出加载后更低的应力应变和卸载后更稳定的形状。结论：（1）支架两次扩张后的应力和塑性应变均在可接受范围之内，并能维持变形后的新形态，验证了治疗理念的可行性；（2）最大应力和塑性应变取决于支架网格连接方式；（3）改善支架网格的连接处可以有效降低应力应变，提高稳定性，减小锥形化。

Abstract:: Abstract: Objective To analyzethe mechanical behaviors of pulmonary valve stents for the treatment of tetralogy of Fallot after balloon dilatation and unloading, thereby evaluating the therapeutic feasibility. Methods Two kinds of pulmonary valve stents with different mesh connection configurations ("X"-shape and "H"-shape) were designed, and the loading process of balloon dilatation and the elastic recoil after removing the balloon were simulated by finite element method. The von Mises stress, equivalent plastic strain and expansion were evaluated, and the effects caused by stent grid connection modes were analyzed.?esults The maximum stress and plastic strain appeared at the stent grid junction, but did not exceed the strength limit. Compared with "X" stent, "H" stent showed a lower stress and strain after loading and maintained a more stable shape after unloading. Conclusion (1) The stresses and plastic strains of stent after twice expansions are within the acceptable range, and can maintain the new shape after deformation, which verifies the feasibility of the treatment concept.(2) The maximum stress and plastic strain depend on the connection mode of stent grid. (3) Improving the connection of stent grid can effectively reduce the stress and strain, improve the stability and reduce the change to cone-shape.