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Harvard Apparatus
Pulsatile Blood Pumps (continued)
Pressure and Flow Curves Using Harvard Pulsatile Blood Pump for
Dogs/Monkeys in Isolated Perfusion of Left Lower Lobe of Dog Lung*
Pressure Curves
The shape of the output pressure curve is a function of both the 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.
Curve A Pressure just beyond the output valve
Curve B Pressure within the pump chamber
Curve C Pressure just before the intake valve
By variation of parameters involved (peripheral resistance, stroke
rate, stroke volume and phase ratio), an infinite number of output
flow characteristics can be obtained.
Hemolysis Test Conditions Models for Dog/Monkey
(PC1 55-5321) and Large Animals (PC1 55-3305)
Hemolysis ranged from 0.114 mg% to 0.29 mg% per pass through
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.
Pa
Pv
Qpa
Pa
Pv
Qpa
Instrumentation:
Pressure Statham
Flow
Pulmonary Artery Pressure
Pulmonary Venous Pressure
Pulmonary Artery Blood Flow
Biotronex Electromagnetic Flowmeter
Recording Electronics for Medicine
*Note: The above data is supplied through the courtesy of Cardiorespiratory
laboratory Columbia-Presbyterian Medical Center New York, New York,
Dr. Alfred P. Fishman, Director.
72 Harvard Apparatus phone 508.893.8999 toll free U.S. 800.272.2775 fax 508.429.5732 www.harvardapparatus.com