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。
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.Results 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.
作者
贾云超
曾赣鹤
陈思
荆腾
贺照明
JIA Yunchao;ZENG Ganhe;CHEN Si;JING Teng;HE Zhaoming(Department of Biomedical Engineering,Research Center of Fluid Machinery Engineering and Technology,Jiangsu University,Zhenjiang 212013,China;Department of Mechanical Engineering,Texas Tech University,Lubbock 79409,USA)
出处
《中国医学物理学杂志》
CSCD
2022年第1期100-108,共9页
Chinese Journal of Medical Physics
基金
国家自然科学基金青年基金(51805218)
江苏省自然科学基金青年项目(BK20170552)
中国博士后面上项目(2018M632239)。
关键词
法洛四联症
肺动脉瓣支架
球囊扩张
塑性变形
有限元分析
tetralogy of Fallot
pulmonary valve stent
balloon dilation
plastic deformation
finite element analysis
