Abstract: An apparatus includes a movable member and a valve coupled to the movable member. The movable member is configured to be disposed within a housing of a medical device and has a first end portion and second end portion. A portion of the first end portion is configured to define a portion of a boundary of a gas chamber. The first end portion defines an opening configured to be in fluid communication between the gas chamber and an area outside the gas chamber. The second end portion is configured to be coupled to a needle configured to deliver a medicament into a body. The valve is configured to selectively allow fluid communication between the gas chamber and the area outside the gas chamber through the opening defined by the first end portion of the movable member.

Abstract: Certain exemplary embodiments comprise an apparatus, comprising: a compressed gas container; a plurality of vials adapted to store a liquid medicament, each vial defining a longitudinal axis, the longitudinal axes of the plurality of vials parallel and non-co-axial, the plurality of vials fluidly coupleable to an actuating portion of a contents of the gas container; and a plurality of pistons, each piston adapted to move within a corresponding vial from the plurality of vials, the plurality of pistons adapted to, in response to discharge of the actuating portion of the contents of the compressed gas container, transfer at least a portion of the liquid medicament from the plurality of vials and through a needle that is extendable into a patient.