The pumping oxygenator: design criteria and first in vitro results.
A new project is presented, the pumping oxygenator, functionally integrating pulsatile pumping and blood oxygenation in a single device. Solid, semipermeable silicone membranes allow gas exchange and simultaneously transfer energy from pressurized gas to blood thanks to their distensibility and to inlet and outlet 1-way valves. Two small-sized (1 m2 exchange surface area) prototypes were designed, constructed, hydraulically characterized, and subjected to gas transfer evaluation tests. Blood flow rates (Q(b)) up to 1,250 ml/min were obtained with 30 mm Hg static preload and 130 mm Hg afterload with 0.7 m upstream and 2.1 m downstream 3/8 inch pipes. Physiological oxygen transfer (VO2 = 5 ml/dl, ml of transferred O2/dl of treated blood) was delivered at Q(b) < 900 ml/min, about 4 ml/dl at Q(b) = 1,250 ml/min. VO2 also was significantly increased by increasing percent systolic time. CO2 transfer decreased regularly with increasing Q(b) from VCO2 = 4.8 ml/dl at Q(b) = 400 ml/min to VCO 2 = 2.1 ml/dl at Q(b) = 1,250 ml/min. The results confirm the possibility of integrating oxygenation and pulsatile pumping. The pumping oxygenator represents a promising project deserving further improvements.
Fiore
G B
GB
Dipartimento di Bioingegneria, Politecnico di Milano, Milan, Italy. fiore@biomed.polimi.it
Costantino
M L
ML
Fumero
R
R
Montevecchi
F M
FM
D001783:Blood Flow Velocity; D002245:Carbon Dioxide / Q000032:analysis; D004867:Equipment Design; D006801:Humans; D008567:Membranes, Artificial; D010100:Oxygen / Q000032:analysis; D010107:Oxygenators, Membrane; D011673:Pulsatile Flow
D008567:Membranes, Artificial; D002245:Carbon Dioxide; D010100:Oxygen