Patent ID: 8870549

Claim:
An actuation system for a reciprocating membrane-based pump having a pumping chamber separated from an actuation chamber by a flexible membrane, a delivery stroke resulting from the application of positive pressure in the actuation chamber, and a fill stroke resulting from the application of negative pressure in the actuation chamber, the actuation system comprising: at least one valve fluidly connecting the actuation chamber with a reservoir arranged to supply positive pressure to the actuation chamber and fluidly connecting the actuation chamber with a reservoir arranged to supply negative pressure to the actuation chamber; a controller configured to signal the at least one valve to operate in a plurality of pulses during a delivery stroke or a fill stroke, each pulse comprising an opening period and a closing period of the valve; wherein the controller is configured to command the at least one valve to pulse with an opening period during an initial phase of a delivery or fill stroke that is longer than an opening period during a later phase of the delivery or fill stroke.