Computational Investigation of a Multilayer Impedance Pump to Serve as an Intra-Aortic Pump

We propose a computational work on an innovative impedance pump, whose design is simple enough to be used as a fully implantable aortic pump. The pump is a multilayered elastic tube of aortic dimensions, and pumping is based on the impedance concept. A thick gelatin-type layer is here added at the fluid interface to amplify the longitudinal elastic waves responsible for the pumping. Small periodic excitations are imposed at a single location on a compliant but not distensible external layer. The combination of those two elastic layers allows significant pumping for very small excitation and without any outward radial displacement. We perform numerical simulations using the finite element method and solve this fully coupled fluid multi-structure interaction problem over a relevant range of frequencies. At the distant exit from the excitation location, mean flow rate varies nonlinearly with frequency. Highest positive exit flow is achieved at resonance, as well as maximum radial distensibility of the gelatin layer. This pumping peak performance is explained by the wave amplification capability of the gelatin layer, making the multilayer gelatin impedance pump an innovative and promising intra-aortic pump design.