The progressive wave pump: numerical multiphysics investigation of a novel pump concept with potential to ventricular assist device application.

This article describes the numerical fluid-structure interaction (FSI) validation of a new pumping concept and the possibility for application of a further developed type, as an implantable ventricular assist device (VAD). The novel principle of the so-called progressive wave pump is based on the interaction of an elastic membrane actuated by forced excitation with a surrounding fluid and the pump housing. By applying forced vibrations to one end of the membrane, a transversal wave builds up and progresses to the far end generating both a positive pressure gradient and flow rate. Among others, two axisymmetric geometrical configurations are possible, namely the discoidal and the tubular design. The first one has been built as a physical prototype and is experimentally investigated. In addition, a corresponding numerical FSI model is set up and validated against the experimental findings. Based on this validated numerical method, further numerical investigations are conducted focusing on the development of a tubular progressive wave pump concept with regard to its potential for application as a VAD in the future. To address VAD-relevant issues such as size, hydraulic performance, and blood trauma, corresponding numerical simulations involving macroscopic blood trauma models have been performed. Although being still in an early phase of development, the results are promising and indicate that the wave pump concept in its present state is feasible and can be further developed and investigated as a new type of blood pump.

A novel, valveless ventricular assist device: the FishTail pump. First experimental in vivo studies.

This article presents the first in vivo experiments with a new type of valveless ventricular assist device, a wave-generating pump. Our goal was to evaluate the hemodynamic performance of the pump by comparing it with the Biomedicus BP-80 centrifugal pump and by sustaining a 3 h long left ventricular assistance. We connected the two pumps in parallel and switched between them. We increased the aspiration by increments of -10 mm Hg at the inlet and measured developed flow, right carotid and femoral pressure, left atrial pressure, and left carotid flow. Then, we let the FishTail perform a 3 h long left ventricular assistance. The mean developed flow on the outlet was higher with the FishTail, with statistical significance, but this difference was not clinically significant. However, we observed an important amount of hemolysis during the ventricular assistance period. Although promising, this novel pumping device needs further prototypes to be clinically applicable.