Evaluation of Hemolysis Caused by a Miniature Heart Catheter Pump

An important performance criterion for blood pumps is blood damage due to the non-physiological loads on the blood cells. Especially for miniature pumps that are inserted into blood vessels in catheter devices and – due to their small diameters - operate at high rotational speeds, hemolysis is an important design issue. The Assistocor heart catheter pump is a left ventricular assist device which is inserted into the Aorta and has an outer diameter of 6.8 mm, it operates at rotational speeds up to 40000 rpm. In-vitro tests with animal blood and different pump prototypes of the Assistocor heart pump showed that hemolysis values stayed below the recommended values for five out of nine of the tested prototypes and are comparable with results from literature, indicating that the design process is adequate to keep the damage of blood cells within acceptable limits despite the high rotational speeds.