DESIGN IMPROVEMENTS OF THE HIA-VAD BASED ON ANIMAL-EXPERIMENTS

Since 1990, development of the Helmholtz-Institute at Aachen ventricul ar assist device (HIA-VAD) was mainly based on animal tests performed at the University of Groningen. Although various in vitro tests had be en performed previously, animal testing resulted in significant improv ements of the HIA-VAD with regard to hemodynamics and pump handling. T he most important design improvement was a new trileaflet polyurethane valve, which was designed as a blood-pump valve with an emphasis on o pening behavior and flow resistance. Excellent hydrodynamic performanc e and sufficient durability of this new valve were confirmed by variou s in vitro tests. Further design and manufacturing improvements result ed in a completely transparent pump, which can be easily deaired and o ptically controlled. Final pump design was evaluated during subsequent animal tests, and the results are very promising in view of an effici ent cardiac support system.