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Artificial cardiovascular organs, termed as mechanical circulatory support (MCS) devices, provide patients with hemodynamics circulatory restoration effectively and vitally but yet are hampered by device-induced adverse events such as thrombotic, embolic and bleeding, which are consequences of blood being chronically exposed to non-pulsatile flow motion and high shear stress. A step forward to better assist heart failure patients, a novel MCS device was proposed aiming at generating a pulsatile blood flow under different systemic vascular resistance and imposing low shear stress on blood elements. Detailed design methods and geometry governing equations were derived first. For this human heart blood circulation application with a flowrate of 0−6LPMand pressure range around 0−160mmHg, a first-generation prototype with a positive displacement of 21.7mL/revdirectly driven by a 70Wbrushless direct current (DC) motor was designed, manufactured and assembled. Computational fluid dynamics (CFD) simulations and bench top experiments were conducted next to characterize the MCS pump and to verify with mathematical models. Finally, the proposed MCS device-mediated hemolysis index was evaluated via CFD simulations and compared with an FDA-benchmark centrifugal MCS pump. This demonstrates potentially higher device hemocompatibility and paves the way for in vitro test in the future.

Supplemental Digital Content is available in the text.Despite growing use of mechanical circulatory support, limitations remain related to hemocompatibility. Here, we performed a head-to-head comparison of the hemocompatibility of a centrifugal cardiac assist system—the Centrimag, with that of the latest generation of an intravascular microaxial system—the Impella 5.5. Specifically, hemolysis, platelet activation, microparticle (MP) generation, and von Willebrand factor (vWF) degradation were evaluated for both devices. Freshly obtained porcine blood was recirculated within device propelled mock loops for 4 hours, and alteration of the hemocompatibility parameters was monitored over time. We found that the Impella 5.5 and Centrimag exhibited low levels of hemolysis, as indicated by minor increase in plasma free hemoglobin. Both devices did not induce platelet degranulation, as no alteration of β-thromboglobulin and P-selectin in plasma occurred, rather minor downregulation of platelet surface P-selectin was detected. Furthermore, blood exposure to shear stress viaboth Centrimag and Impella 5.5 resulted in a minor decrease of platelet count with associated ejection of procoagulant MPs, and a decrease of vWF functional activity (but not plasma level of vWF-antigen). Greater MP generation was observed with the Centrimag relative to the Impella 5.5. Thus, the Impella 5.5 despite having a lower profile and higher impeller rotational speed demonstrated good and equivalent hemocompatibility, in comparison with the predicate Centrimag, with the advantage of lower generation of MPs.