Air supply mechanism for ventricular assist system

A pump system has a rotatory shaft and a rotatory drive arrangement coupled to the rotatory shaft for applying rotatory energy thereto. First through fourth pump arrangements are coupled to the rotatory shaft, each pump arrangement pumping a pulse of air during each rotation of the rotatory shaft, the first, second, third, and fourth pump arrangements pumping a corresponding pulse of air sequentially during each rotation of the rotatory shaft. The rotatory shaft has a first and second ends, and a central region therebetween where an electric motor is coaxially arranged. The first and third pump arrangements are coupled to the first end of the rotatory shaft, and the second and fourth pump arrangements are coupled to the second end of the rotatory shaft. Angularly displaced eccentric couplers couple the pump arrangements to the respective ends of the rotatory shaft.