Laboratory experience with a novel, non-occlusive, pressure-regulated peristaltic blood pump

Current blood pumps have potential safety problems, including the ability to generate extreme positive and negative pressures. These problems were addressed in the design and testing of a non-occlusive, peristaltic blood pump. The pump consists of a tubing of unique design (pump chamber) wrapped under tension around a rotor with rollers. The pump chamber design is such that the pump is passively filling; flow is dependent upon the pressure of the blood supply and the size of the pump chamber. Thus, negative pressures cannot be generated. With the outlet occluded, the pump produces the maximum attainable pressure, which can be set by adjusting the tension of the pump chamber around the rollers. The design characteristics make the pump suitable for prolonged use. The pump was tested in vitro for pressure safety, hemolysis, and durability. The pump prototype was used in 25 experiments involving extracorporeal circulation on sheep, with an average duration of approximately 6 hr and bypass flow rates between 0.5 and 2.0 L/min. No pump related complications occurred in any of these experiments. The pump described here is suitable for short- and long-term perfusion applications, and does not require additional pressure regulation, as do current blood pumps.