Computer assisted design for the implantable left ventricular assist device (LVAD) blood pump using computational fluid dynamics (CFD) and computer-aided design and manufacturing (CAD/CAM)
Computer assisted design for the implantable left ventricular assist device (LVAD) blood pump using computational fluid dynamics (CFD) and computer-aided design and manufacturing (CAD/CAM)
复制标题
使用计算流体动力学 (CFD) 和计算机辅助设计和制造 (CAD/CAM) 进行植入式左心室辅助装置 (LVAD) 血泵的计算机辅助设计
DOI：
10.1007/bf02479895
复制
发表时间：
2001
影响因子：
1.3
通讯作者：
Y. Mitamura
中科院分区：
文献类型：
--
作者：
E. Okamoto;Shinichiro Fukuoka;E. Iwazawa;Y. Mitamura
血栓形成和溶血是长期可植入的左心室辅助系统设计中的关键问题。血液流动的流体动力学特性是导致血栓形成和溶血的主要因素之一。在这项研究中，我们优化了我们的植入型LVAS中的血腔几何形状、端口设计和流体动力学，以确保最大限度地减少与剪应力相关的血液损伤。用三维CAD(计算机辅助设计)软件(Pro-Engineering版本20)设计了血泵腔(每搏输出量为65ml)和进、流出流口，并用有限元(Finish-Element)计算流体动力学(CFD)分析(Ansys版本5.5)进行了估算。我们采用CFD结果的三维分布进行定性评价，并尝试从CFD分析结果中估计归一化溶血指数(NIH)和红细胞压积的时间序列变化作为血泵腔体几何形状优化的定量指标。在此基础上，对血泵的几何形状进行了优化，使血泵的NIH从第一个模型的2.72g/1001降到第二个模型的0.098 g/1001，相应地降低了切应力。植入泵2年后，红细胞压积也由模型1的0.7%提高到模型2的11.5%。在第一个模型中观察到流动停滞的区域在第二个模型中没有停滞。结果表明，血泵的计算机辅助设计有助于优化血泵腔，以减少血栓形成和溶血，并有助于降低成本和时间。
Thrombus formation and hemolysis are critical issues in the design of a long-term implantable LVAS (left ventricular assist system). The fluid dynamic characteristics of the blood flow are one of the main factors that cause thrombus formation and hemolysis. In this study, we optimized blood chamber geometry, port design, and fluid dynamics in our implantable LVAS to ensure minimization of shear-stress-related blood damage. A blood pump chamber (stroke volume, 65 ml) and an inflow and outflow port were designed with three-dimensional CAD (computer-aided-design) software (Pro-Engineering version 20) and estimated by FEM (fine-element method) computational fluid dynamic (CFD) analysis (Ansys version 5.5). We adopted three-dimensional distribution of CFD results for qualitative evaluation, and we also tried to estimate the normalized index of hemolysis (NIH) and time-series change of hematocrit from the results of CFD analysis as quantitative index of optimization for geometry of the blood pump chamber. With the use of this design, the blood pump geometry was optimized as the decrease of NIH from 2.72 g/1001 in the first model to 0.098 g/1001 in the second model, corresponding to the decrease in shear stress. The hematocrit also improved from 0.7% in the first model to 11.5% in the second model 2 years after implantation of the pump. Areas where flow stagnation was observed in the first model were free of stagnation in the second model. The results show that computer-aided design of the blood pump contributes to optimizing a blood pump chamber for reducing thrombus formation and hemolysis, and also contributes to reducing cost and time in developing the implantable LVAS.