Significant safety advantages gained with an improved pressure-regulated blood pump.
A prototype of a non-occlusive pressure-regulated blood pump (M-pump) was evaluated in-vitro for safety in a comparative study with the roller and centrifugal pumps. The M-pump consists of collapsible tubing of unique design wrapped under tension around a rotor without a stator. The prototype M-pumps were tested in vitro to evaluate performance with respect to flow/ pressure characteristics, hemolysis, bubble generation (cavitation) and durability. The M-pump and centrifugal pump did not overpressurize at any RPM when the pump outlet was occluded, but the roller pump reached pressures in excess of 1000 mmHg. The M-pump did not generate negative pressures upon occlusion of the inlet, whereas the roller and centrifugal pumps produced near-vacuum pressures. Furthermore, the M-pump was unable to empty a blood reservoir when the height of the pump inlet was placed slightly above the reservoir outlet. The levels of microbubbles in the M-pump were significantly lower than the roller and centrifugal pumps upon sudden restriction of the pump inlet as determined with an ultrasonic bubble detector. The results of our in-vitro evaluation of the M-pump have shown it to have lower hemolysis than the centrifugal pump and lower or comparable hemolysis to roller pumps at flowrates of 0.1, 0.5, 4.0 and 6 L/min. We determined that the M-pump design possesses important safety advantages over roller and centrifugal pumps for cardiopulmonary bypass applications.
Montoya
J P
JP
MC3, Inc., Ann Arbor, Michigan 48103, USA.
Merz
S I
SI
Bartlett
R H
RH
D000388:Air; D002315:Cardiopulmonary Bypass / Q000295:instrumentation*; D004389:Durable Medical Equipment; D004867:Equipment Design; D004868:Equipment Failure; D004869:Equipment Safety; D005112:Extracorporeal Circulation / Q000295:instrumentation; D006461:Hemolysis; D018056:Hemorheology; D006801:Humans; D008422:Materials Testing; D011312:Pressure; D014618:Vacuum