Li Hongxia, Zhang Yihao, Zhu Bao, Wu Jinying, Wang Xicheng
State Key Laboratory of Structural Analysis for Industrial Equipment, Department of Engineering Mechanics, Dalian University of Technology, Dalian 116024, China.
Surface Engineering Laboratory, School of Materials Science and Engineering, Dalian University of Technology, Dalian 116024, China.
ScientificWorldJournal. 2013 Dec 29;2013:827839. doi: 10.1155/2013/827839. eCollection 2013.
The drug release analysis and optimization for drug-eluting stents in the arterial wall are studied, which involves mechanics, fluid dynamics, and mass transfer processes and design optimization. The Finite Element Method (FEM) is used to analyze the process of drug release in the vessels for drug-eluting stents (DES). Kriging surrogate model is used to build an approximate function relationship between the drug distribution and the coating parameters, replacing the expensive FEM reanalysis of drug release for DES in the optimization process. The diffusion coefficients and the coating thickness are selected as design variables. An adaptive optimization approach based on kriging surrogate model is proposed to optimize the lifetime of the drug in artery wall. The adaptive process is implemented by an infilling sampling criterion named Expected Improvement (EI), which is used to balance local and global search and tends to find the global optimal design. The effect of coating diffusivity and thickness on the drug release process for a typical DES is analyzed by means of FEM. An implementation of the optimization method for the drug release is then discussed. The results demonstrate that the optimized design can efficiently improve the efficacy of drug deposition and penetration into the arterial walls.
研究了动脉壁中药物洗脱支架的药物释放分析与优化，这涉及力学、流体动力学和传质过程以及设计优化。采用有限元法（FEM）分析药物洗脱支架（DES）在血管中的药物释放过程。克里金代理模型用于建立药物分布与涂层参数之间的近似函数关系，在优化过程中取代了对DES药物释放进行昂贵的有限元法重新分析。选择扩散系数和涂层厚度作为设计变量。提出了一种基于克里金代理模型的自适应优化方法来优化药物在动脉壁中的存留时间。自适应过程通过一种名为预期改进（EI）的填充采样准则来实现，该准则用于平衡局部搜索和全局搜索，并倾向于找到全局最优设计。通过有限元法分析了涂层扩散率和厚度对典型DES药物释放过程的影响。然后讨论了药物释放优化方法的实现。结果表明，优化设计可以有效地提高药物在动脉壁中的沉积和渗透效果。
