An operating system for a medical device pump has a microprocessor controlling the operation of the pump features in a manner to minimize power consumption and maximize the life of the batteries powering the pump. The microprocessor associated with the medical device pump includes a modulation circuit that operates the pump on an intermittent basis and only when a pressure sensor indicates that the pressure asserted by the pump is at a threshold level. The operation of other sensors 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 modulation circuit. A fill sensor is operated intermittently, while a tilt sensor is only activated when a signal is received from the fill sensor. An optical sensor is only activated when the canister is removed from the pump housing, during which the pump is de-powered.
