laboratoryColumbia-PresbyterianMedicalCenterNewYork,NewYork,
Dr.AlfredP.Fishman,Director.
pump action and the characteristics of the external system on the
output valve side. The following set of curves were obtained with
Model 1421, using water as the pumped medium. In the tests,
"Sanborn" pressure transducers were inserted in three places, and
continuous records obtained under varying conditions.
rate, stroke volume and phase ratio), an infinite number of output
flow characteristics can be obtained.
(PC5 55-5321) and Large Animals (PC5 55-3305)
the various pumps, with an error of ±10%.
To put these results in perspective, most physiological perfusions
are run with flow rates and total blood primes, such that the number
of passes through the pump will range from about 1/4 to 3/4 per
minute. Assuming one pass in two minutes and no physiological
removal of the products of hemolysis, then hemolysis rates would
range from 3.4 mg% to 8.7 mg% per hour of pump use.
In these studies a reservoir of 500-800 cc of fresh dog blood was
used, connected to the pump by 3/8" PVC tubing. Samples at
room temperature were taken at 15 and 30 minute intervals for
4 to 5 hours. Samples were spun down and hemolysis measured
immediately using the method of Flink and Watson. Since the rate
of hemolysis depends on the amount of blood in the system and the
flow rate, the results are reported as mg% per pass. The flow rate
divided by the volume of blood in the system determines the number
of passes through the pump per minute.