Activation Mechanism Design for a Dual-Blood Pumping System for Pediatric Heart Failure

Abstract

Objective: Pediatric patients face significant challenges in the treatment of end-stage congenital or acquired heart failure (HF). Mechanical circulatory support (MCS) devices can serve as a bridge to transplant, but the few available MCS solutions are associated with deleterious patient outcomes when compared to adults. We are working to address this gap by developing a novel double-blood pump VAD to provide effective single-device support across the pediatric age range. Our innovative design integrates both an axial pump and a centrifugal pump in one implantable device and utilizes a unique mechanism to activate the secondary centrifugal pump as cardiac demands increase.

Methods: We developed a configuration for the novel activation mechanism through virtual studies against functional requirements and anatomical fit constraints, iteratively improved the activation mechanism design to meet qualitative and quantitative design targets, evaluated the design through in vitro functional and hydraulic experimentation, and determined the hemolytic profile of the proposed design through hemolytic flow loop testing and analysis.

Results: Multiple iterations of design improvements resulted in a prototype that could effectively and repeatably actuate in situ while providing leak-free support at physiological pressures and flows. Hemolytic testing demonstrated that the blood damage potential is low.

Conclusion: The results from this study validate the proposed activation mechanism design and support the continued translational development of the Drexel Double Dragon VAD.

Keywords: pediatric blood pump; pediatric circulatory support; pediatric total artificial heart; ventricular assist device.