Abstract
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.