Abstract: A dual piston-pump apparatus is provided having a pump chassis that includes a pair of spaced-apart, elongated piston bores, and a lead screw shaft. This shaft includes a motor driven end, and another portion thereof rotatably mounted to the chassis for rotation about a screw rotational axis. A piston drive member threadably cooperates with the lead screw shaft for selective reciprocating movement longitudinally along the screw rotational axis thereof between a first position and a second position. The drive member includes a pair of spaced-apart piston shafts, each piston shaft of which includes a respective piston head slideably received in a respective piston bore of the chassis. As the drive member is driven along the screw shaft between the first position and the second position, each piston head is simultaneously reciprocated between a dispensing condition and an aspiration condition.