BASIC PERFORMANCE OF A MINIATURE INTRAVENTRICULAR AXIAL PUMP

A miniature intraventricular axial pump for left ventricular (LV) supp ort is under development. This pump was designed for placement in the LV cavity by insertion through the LV apex with the outlet located at the ascending aorta via the aortic valve, The basic hydrodynamic chara cteristics represented as a relationship between pump head (H) and flo w (Q) showed a negative linear relationship under a constant head. Thi s characteristic was generally the same as that obtained by other axia l rotation pumps. However, the actual H-Q relationship was represented as anticlockwise ''loops'' caused by the contraction of the natural L V. The comparative in vitro data on these H-Q loops showed that the sh ape of the loops was changed drastically by the connecting condition b etween the pump and natural cardiovascular system.