摘要
针对适形贴壁支架“适形”和“可行”的矛盾,探究不同平滑设计方案对支架力学行为和贴壁效果的影响。基于三维投影方法,对投影区域用最小二乘法进行拟合(拟合阶数1~6分别对应模型1~6),达到对适形贴壁支架平滑的效果。模拟6组支架在斑块钙化程度不同的狭窄血管中的压握、扩张过程,分析了弯曲刚度、支架崎岖度、面积残余狭窄率、接触面积分数和接触体积分数等指标。结果显示,弯曲刚度、支架崎岖度、面积残余狭窄率、接触面积分数和接触体积分数均随拟合阶数的增加呈上升趋势。其中模型1的接触面积分数和接触体积分数最小,未完全钙化斑块环境中分别为77.63%和83.49%,完全钙化斑块环境中分别为72.86%和82.21%,“适形”性最差;模型5和6的支架崎岖度的值较为接近,分别为32.15%和32.38%,制造和植入的“可行”性最差;模型2、3、4在两种斑块环境中具有相近的面积残余狭窄率。可见,对投影区域用最小二乘法进行2~4阶拟合获得适形贴壁支架较为合理;其中,在完全钙化环境中,2阶拟合获得的适形贴壁支架性能更好。
To address the conflict between the“fitness”and“feasibility”of body-fitted stents,this paper investigates the impact of various smoothing design strategies on the mechanical behaviour and apposition performance of stent.Based on the three-dimensional projection method,the projection region was fitted with the least squares method(fitting orders 1–6 corresponded to models 1–6,respectively)to achieve the effect of smoothing the body-fitted stent.The simulation included the crimping and expansion process of six groups of stents in stenotic vessels with different degrees of plaque calcification.Various metrics were analyzed,including bending stiffness,stent ruggedness,area residual stenosis rate,contact area fraction,and contact volume fraction.The study findings showed that the bending stiffness,stent ruggedness,area residual stenosis rate,contact area fraction and contact volume fraction increased with the fitting order's increase.Model 1 had the smallest contact area fraction and contact volume fraction,77.63%and 83.49%respectively,in the incompletely calcified plaque environment.In the completely calcified plaque environment,these values were 72.86%and 82.21%,respectively.Additionally,it had the worst“fitness”.Models 5 and 6 had similar values for stent ruggedness with 32.15%and 32.38%,respectively,which indicated the worst"feasibility"for fabrication and implantation.Models 2,3,and 4 had similar area residual stenosis rates in both plaque environments.In conclusion,it is more reasonable to obtain the body-fitted stent by using 2nd to 4th order fitting with the least squares method to the projected region.Among them,the body-fitted stent obtained by the 2nd order fitting performs better in the completely calcified environment.
作者
孙浩
陶克怡
刘昭
杜田明
张艳萍
刘圣文
冯继玲
乔爱科
SUN Hao;TAO Keyi;LIU Zhao;DU Tianming;ZHANG Yanping;LIU Shengwen;FENG Jiling;QIAO Aike(College of Chemistry and Life Science,Beijing University of Technology,Beijing 100124,P.R.China;Beijing International Science and Technology Cooperation Base for Intelligent Physiological Measurement and Clinical Transformation,Beijing 100124,P.R.China;Department of Cardiology,Fuwai Hospital,Chinese Academy of Medical Sciences,Beijing 100032,P.R.China;Department of Engineering,Faculty of Science and Engineering,Manchester Metropolitan University,M15GD,Manchester,UK)
出处
《生物医学工程学杂志》
EI
CAS
北大核心
2024年第4期790-797,806,共9页
Journal of Biomedical Engineering
基金
国家自然科学基金(12172018)
国家自然科学基金委员会与英国皇家学会合作交流项目(IEC\NSFC\223003)。
关键词
血管内支架
结构设计
支架贴壁不良
数值模拟
生物力学
Endovascular stent
Structure design
Stent malapposition
Numerical simulation
Biomechanics
