Abstract: A medication pump includes a housing including an external wall and a plurality of internal adjoining housings, including a first housing enclosing a cartridge. The pump includes a primary vent for venting the medication pump to atmosphere, the primary vent including a primary liquid barrier allowing passage of gas therethrough while preventing passage of liquid therethrough. The pump includes a secondary vent on the first housing, the secondary vent including a secondary liquid barrier allowing passage of gas therethrough to an interior of the housing while preventing passage of liquid therethrough.

Abstract: The present invention concerns a medication pump for use with a medication cartridge that is loaded using a drive rod of the medication pump. In one embodiment, the drive rod includes an interface structure defining a first channel where the first channel has an axial portion disposed parallel to an axis of the drive rod and a locking portion disposed in a circumferential direction around an outer surface of the drive rod. In another embodiment of the invention, the drive rod includes a visual indicator at an interface end of the drive rod, so that when the interface structure of the drive rod is coupled to a plunger of a medication cartridge, the visual indicator will not be seen, to provide a way to check for secure coupling of the drive rod to the plunger. In its embodiment, the outer housing of the medication pump includes a window into a cartridge housing to allow a view of the visual indicator if it is not attached to the plunger.