Objective To optimize the hemodynamics of a disk blood pump in children. Method We used the computational fluid dynamics technology to simulate the flow in a pediatric blood pump numerically, and finally analyzed the results for deep study about the thrombosis and hemolysis produced in it, to improve the design according to the results of the flow field analysis. Results We calculated results between the flow rate and the pressure elevation at different rotational speed: 2 500 rpm, 3 000 rpm, and 4 000 rpm, respectively. Under each rotational speed, it was selected five different discharge outlet boundary conditions. The simulation results conformed to the experimental data. The increased pressure of the blood pump was effective. But the phenomenon of flow separation was increased the at blade surface in the low speed region. The maximum wall shear stress was maintained within 100 Pa. Conclusion The design of disc blood pump has a good fluid dynamic performance. And the flow line is fluent, the probability of thrombosis and hemolysis occurred is in the range of control. But the phenomenon of flow separation is appeared. There is a room to improve.
Blood pump is the core component of artificial ventricular assist device, and thrombosis is a severe complication of blood pump in clinical application. Methods of controlling and reducing thrombosis include materials surface modification, structure and parameters optimization of blood pump, and others. The typical symptoms of thrombosis and the hazard of various types of blood pump, the formation mechanism and primary factors for thrombosis, and the simulation prediction models for thrombosis were reviewed in this paper.
In vitro hemolysis testing for blood pumps currently faces several challenges, including randomness in control group selection, and numerous sources of uncertainty in the testing methods. These issues lead to high uncertainty, insufficient result credibility, and limited comparability, which hinders the effective evaluation of blood damage induced by blood pumps. This study aims to address these limitations by developing a magnetically-levitated blood pump benchmark model and optimizing the hemolysis testing protocol to reduce result uncertainty. A magnetic bearing was utilized to minimize blood damage, and the injection molding was employed to enhance the machining precision of the pump. The experimental procedures, including blood collection, test loop setup, and the testing process, were optimized to effectively control experimental uncertainty. The results showed that the performance curve of the benchmark pump model was flat, and the coefficient of variation for the hydraulic experimental results was less than 5%. The secondary flow path exhibited good blood washout with no thrombus formation. Under low-flow condition, the average normalized index of hemolysis (NIH) was 0.014 g/100L, with a coefficient of variation of 19.50%. Under high-flow condition, the average NIH was 0.045 g/100L, with a coefficient of variation of 16.45%. The hemolysis values under both conditions were lower than the Abbott CentriMag. In conclusion, we designed a benchmark blood pump model with excellent hemocompatibility and optimized hemolysis testing protocol, which led to low uncertainty in experimental results. The benchmark and optimized hemolysis protocol help to improve the credibility and comparability of in vitro hemolysis testing data, providing a reliable solution for both the industry and regulatory agencies to assess hemocompatibility.