The total artificial heart (TAH) being developed by these authors successfu
lly completed hydrodynamic and hemolysis studies followed by two acute impl
antations. Before commencing preclinical studies on any device, documentati
on of the reliability and durability of each component has to be done. This
TAH was submitted to a 4 month destruction test under the most severe driv
ing conditions to detect any weak mechanical components of the system. The
maximum dP/dt in the left pumping chamber was chosen of more than 15,000 mm
Hg/s, which is almost 6 times higher than that of the normal driving condi
tion. The pump was submersed into a water bath that was maintained at 37 de
grees C. The TAH was driven in a left master alternative (LMA) variable rat
e mode at 8 L/min output flow, 15 mm Hg preload, 100 mm Hg left afterload,
and 25 mm Hg right afterload. The outflow, pressures, and temperature insid
e the TAH were monitored. Several stress concentration areas were detected.
The connection between the roller nut and support plate proved to be one o
f the most stressed regions, and a more reliable fixing procedure was requi
red. This portion was redesigned to offer a durable connection. No malfunct
ions of the actuator or controller were detected throughout the testing dur
ation. No temperature elevation more than 1 degrees C on the center piece o
f the TAH was demonstrated.