Integrated long-term multifunctional pediatric mechanical circulatory assist device.

ABSTRACT

There continues to be limited, viable ventricular assist device technology options to support the dysfunctional states of pediatric heart failure. To address this need, we are developing a magnetically suspended, versatile pumping technology that uniquely integrates two blood pumps in a series configuration within a single device housing. This device enables operational switching from the usage of one pump to another as needed for clinical management or to support growth and development of the pediatric patient. Here, we present the initial design where we conducted a virtual fit study, the Taguchi Design Optimization Method, iterative design to develop pump geometries. Computational tools were used to estimate the pressure generation, capacity delivery, hydraulic efficiency, fluid stress levels, exposure time to stresses, blood damage index, and fluid forces on the impellers. Prototypes of the pumps were tested in a flow loop using a water-glycerin solution. Both designs demonstrated the capability to generate target pressures and flows. Blood damage estimations were below threshold levels and achieved design requirements; however, maximum scalar stress levels were above the target limit. Radial and axial forces were less than 1 N and 10 N, respectively. The performance data trends for physical prototypes correlated with theoretical expectations. The centrifugal prototype was able to generate slightly higher pressure rises than numerical predictions. In contrast, the axial prototype outperformed the computational studies. Experimental data were both repeatable and reproducible. The findings from this research are promising, and development will continue.