| abstract |
A drug delivery device, including a body having a reservoir disposed therein for containing a medicament, the reservoir including a flexible wall; a plunger movable within the body for causing the medicament to be expelled from the reservoir, the plunger having a contact surface that is not affixed to said flexible reservoir wall; a spring biasing the plunger toward the reservoir; and means for selectively maintaining the plunger in a pre-activated position with respect to the reservoir and, upon releasing the plunger from the pre-activated position, for guiding the plunger to move under the force of the spring such that the contact surface of the plunger contacts the flexible reservoir wall to pressurize the reservoir for delivery of the medicament to a patient. |