A pump unit (10) includes a number of pumps (14) each having a port in fluid connection to a combined port (12) of the pump unit. A processing system (16) is connected to each of the pumps (14) for independent actuation of each pump. A user interface (22) allows user actuation of the pump unit according to one or more mode of operation, requiring various different levels of suction or pressure. The processing system (16) determines what number of pumps (14) is required, and selectively actuates pumps in order to generate the required suction or pressure. Particularly preferred applications include breast pumps. Additional aspects of the invention relate to a cyclic pulsed suction profile generated by the device, implementations that detect when a milk extraction set is not properly deployed, and configurations which allow a touch screen to be used as a power-on switch for the device.