Abstract: The pump comprises two separate pumping units, one each for the systemic and pulmonary circulation systems. Each pumping unit has an outer housing enclosing a cylindrical pumping chamber. Two radially extending vanes are contained within each chamber and divide the chamber into two separate subchambers, the relative size of which varies as the vanes rotate through the pumping cycle. Pumping action is achieved when one of the vanes is held stationary while the other vane rotates. This causes one subchamber to decrease in size. This subchamber is disposed over an outlet port and the blood is forced out of that subchamber. The other subchamber is increasing in size and is disposed over an inlet port. Blood enters this inlet chamber both in a passive manner and through the suction caused by the increasing size of the subchamber. A sensor is positioned near the inlet port and measures the volume of blood entering through this port.