Numerical Design of a Partial-Support Axial Blood Pump

Partial-support is the main support mode for “less sick” patients with severe heart failure. But there were fewer partial-support blood pumps for clinical use. An implantable partial-support axial blood pump was developed for heart failure patients. To gain better hemolytic performance and lower pump thrombus risk, the rotor blades were extended to the contractive section of the rotor hub while cone-bearing was adopted. The hydraulic and hemolytic performance of the blood pump was simulated and analyzed by computational fluid dynamics (CFD) method. The flow velocity, hydraulic efficiency, exposure time, scalar shear stress (SSS) and hemolytic performance of the axial blood pump was analyzed. The numerical results showed that the axial blood pump could produce a 1–8 Lpm flow rate with a 54.7–186.7 mmHg pressure head when the pump rotating from 9000 to 13000 rpm. The hydraulic efficiency and SSS distribution corresponded with the typical performance of a blood pump. The mean hemolysis index of the blood pump calculated by the Giersiepen’s model was 5.0 × 10−5%. After extending the rotor blades to the contractive section of the rotor hub, the spiral flow at the inlet of the rotor impeller was reduced. Hemolysis in the blood pump was improved because the exposure time was reduced and the blood damage caused by SSS was reduced.. The designed blood pump satisfies the clinical requirements of partial-assist for less-sick heart failure patients.