The roller pump, used to pump blood flow during cardiopulmonary bypass and to provide long-term circulatory support, is a constant blood-flow device. It maintains constant flow independently of the clinically expected changes in inlet pressures. A decrease in blood supply to the inlet of the pump without a concomitant decrease in pump speed can cause excessive suction leading to air embolism, thrombosis, and damage by the "venous" cannula to the vessel's intima or, with a bubble oxygenator, the emptying of the oxygenator, pumping air to the patient. The purpose of this research is to design, fabricate, and evaluate a new, innovative disposable pump chamber for the standard roller pump that self-controls the pump flow as a function of inlet or filling pressure, much like the natural heart. The pump chamber consists of an easily collapsible thin-wall tubing (TWT) housed and sealed in a standard pump tubing. The inner TWT serves to pump blood and the outer tubing serves as a mechanical support and controlled pressure environment for the TWT. This pump chamber can provide additional safety during open heart surgery and also function as an inexpensive, self-controlling mechanism for long term circulatory support. National Heart, Lung, and Blood Institute (NHLBI)
