Patent ID: 6682504
Filing Date: 2004-01-27
Classification: A61M,Y10S

Abstract:
A jet injector comprising:a cartridge assembly for holding medicament, the cartridge assembly having proximal and distal ends and comprising: a chamber having proximal and distal ends for holding the medicament therein; an orifice at the proximal end of the cartridge assembly; a stopper at the proximal end of the chamber; and a plunger at the distal end of the chamber and movable towards the stopper to expel medicament out of the chamber through the orifice; and a power pack assembly comprising: a housing having a proximal end operatively coupled with the distal end of the cartridge assembly; a trigger; and an energy source operatively associated with the trigger so that movement of the trigger causes the energy source to move the plunger toward the stopper to expel medicament from the chamber, wherein the energy source comprises a gas spring of a spring material in a gaseous phase and a charging portion of the spring material in a liquid phase that is in equilibrium with the gaseous phase for compensating for leakage to maintain a pressure of the gas spring prior to activation sufficient for expelling and injecting the medicament, wherein the energy source is configured for releasing the gas after the expelling of the medicament.