An operating system for a medical device pump (11) has a microprocessor (51) controlling the operation of the pump (11) features in a manner to minimize power consumption and maximize the life of the batteries (57) powering the pump (11). The microprocessor (51) associated with the medical device pump (10) includes a drive circuit that operates the pump (10) on an intermittent basis and only when a pressure sensor (55) indicates that the pressure asserted by the pump (10) is at a threshold level. The operation of other sensors (30, 38, 39) are powered only in situations when information from the sensor is needed, while other more essential sensors are operated on an intermittent basis by the drive circuit. A fill sensor (38) is operated intermittently, while a tilt sensor (39) is only activated when a signal is received from the fill sensor (38). An optical sensor (30) is only activated when the canister (20) is removed from the pump housing (12), during which the pump (11) is de-powered.
