Geometric Optimization of an Extracorporeal Centrifugal Blood Pump with an Unshrouded Impeller Concerning Both Hydraulic Performance and Shear Stress

Bo Huang,Qingyu Wu,Zhigang Zuo,Bin Lu,Shuhong Liu,Miao Guo

doi:10.3390/pr9071211

Abstract

Centrifugal blood pumps have provided a powerful artificial support system for patients with vascular diseases. In the design process, geometrical optimization is usually needed to acquire a more biocompatible model for clinical uses. In the current paper, we propose a method for multi-objective optimization concerning both the hydraulic and the hemolytic performances of the pump based on the near-orthogonal array in which the traditional hemolysis index (HI) is replaced with the maximum scalar shear stress criteria to reduce the computation load. The method is demonstrated with the optimization of an extracorporeal centrifugal blood pump with an unshrouded impeller. CFD studies on the original and nine modified pump models are carried out. The calculated hydraulic performances of the optimized model are also compared against the experiments for validation of the numeric method, with an error of 3.6% at the original design point. The resulting blood pump with low maximum scalar shear stress (132.2 Pa) shows a low degree of calculated HI (1.69 × 10−3).

Highlights

This paper presents an optimization method based on the near-orthogonal array concerning both the hydraulic and the hemolytic performances of the centrifugal blood pump by varying multiple geometric parameters
A simplified hemolysis criterion is adopted in this study in terms of the maximum scalar shear stress (SSS)
The results indicate that the hemolysis index (HI) of the models with large-curved blades of 16 lower than small-curved blades

Summary

Introduction

Publisher’s Note: MDPI stays neutral with regard to jurisdictional claims in published maps and institutional affiliations. Blood pumps containing rotating impellers have been widely used to provide or assist the blood recirculation in clinical applications, including the intraoperative extracorporeal circulation, the extracorporeal membrane oxygenation (ECMO), and the left ventricular assist devices (LVAD). The prevailing products in these fields adopt centrifugal impellers, such as Rotaflow (Maquet, Jostra Medizintechnik AG, Hirrlingen, Germany) and Heartmate. 3 (St. Jude Medical, Inc., Pleasanton, CA, USA), and are characterized by lower rotating speeds compared with their axial counterparts. Centrifugal blood pumps show great potential as a life-saving technology, a relatively high risk of postoperative complications induced by hemolysis or thromboembolism of the patients has been reported [1,2].

Methods

Discussion

Conclusion