A peristaltic pump (22) includes a conduit (50) having a first end for receiving a fluid from a reservoir (24) and a second end for delivering the fluid. A plurality of fingers (34) are disposed at respective locations along a segment of the conduit and are configured to alternately compress and release the conduit at the locations. A cyclical pump mechanism (42) is coupled to move the fingers between respective compressed and released positions in a spatio-temporal pattern so as to drive a predetermined quantity of the fluid through the segment of the conduit in each pump cycle. A motor (40) is coupled to drive the pump mechanism. A controller (48) is coupled to activate and deactivate the motor in alternation during each pump cycle with a duty cycle that varies within the pump cycle.
