Clinically Motivated Redesign of the Pennsylvania State University Child Ventricular Assist Device

Building on validated in vitro and chronic in vivo testing of the Penn State University (PSU) Child Ventricular Assist Device (CVAD), the four-bladed prototype rotor (Rev 0.0) was redesigned using established analytical and computational methods to improve hydraulic efficiency while preserving hemodynamic performance and biocompatibility. Applying turbomachinery principles at the nominal operating condition (3 liters/minute [LPM], 8,000 revolutions/minute [RPM]), a five-bladed design (Rev 1.0) was created with an ideal inflow angle (β1 = 41.0°) and outflow angle (β2 = 27.4°). In silico simulations of Rev 1.0 across the prototype's operating range (7,000-9,000 RPM, 1-5 LPM) demonstrated an approximately 40% improvement in hydraulic performance. The Rev 1.0 rotor was then evaluated on a benchtop mock circulatory loop using fresh ovine blood, confirming the in silico gains. The normalized index of hemolysis (NIH), measured at two clinically relevant conditions (1.5 LPM and 3.3 LPM, both at ~80 mm Hg), was 0.052 ± 0.054 and 0.047 ± 0.033 mg/dL, respectively, and high-molecular-weight multimers of von Willebrand factor were preserved within normal to borderline ranges. By achieving target flows and pressures at approximately 1,000 RPM lower speeds, the redesign reduces power requirements and enables longer untethered operation, advancing a fully implantable PSU CVAD toward a critical unmet need in pediatric advanced heart failure.