Technical guidelines nowadays recommend and regulate the use Computational Fluid Dynamics (CFD) to assess the performance of medical devices. CFD coupled to blood damage models has emerged as a powerful tool to evaluate the hemocompatibility of blood recirculating devices. The present study is aimed at evaluating the hydrodynamic performance and the thrombogenic potential of two prototypes of magnetically levitating centrifugal pumps. The two devices differ in the impeller configuration - 6-blades vs. 12-blades – and have been designed to be used in Cardiopulmonary Bypass (CPB) circuits during open heart surgery and in Extracorporeal Membrane Oxygenation (ECMO) to support patients with severe cardiac or respiratory failure. The pumps have been modelled using Direct Numerical Simulation coupled to Lagrangian analysis to predict platelet activation due to abnormal shear stress histories. Numerical results have been compared with experimental data in terms of head generation for different working points. Results show that the 6-blades pump has i) smaller stagnation areas, ii) lower stress levels and iii) higher strain rate, resulting in a lower thrombogenic potential, whereas the 12-blade impeller guarantees a more stable performance at high flow rates, suggesting its preferential use for more demanding applications, such as CPB.

现在的技术指南推荐和规范使用计算流体动力学 (CFD) 来评估医疗设备的性能。结合血液损伤模型的 CFD 已成为评估血液再循环装置的血液相容性的强大工具。本研究旨在评估两种磁悬浮离心泵原型的流体动力学性能和血栓形成潜力。这两种设备的叶轮配置不同 - 6 叶片与 12 叶片 - 设计用于心脏直视手术期间的心肺旁路 (CPB) 回路和体外膜氧合 (ECMO) 以支持患有严重心脏病的患者或呼吸衰竭。泵已使用直接数值模拟与拉格朗日分析相结合进行建模，以预测由于异常剪切应力历史引起的血小板活化。在不同工作点的水头生成方面，数值结果与实验数据进行了比较。结果表明，6 叶片泵具有i ) 较小的停滞区域，ii ) 较低的应力水平和iii ) 较高的应变率，导致血栓形成的可能性较低，而 12 叶片叶轮可确保在高流速下具有更稳定的性能，表明其优先用于要求更高的应用，比如CPB。