Patent ID: 6689093
Filing Date: 2004-02-10
Classification: A61M

Abstract:
A needle-less hypodermic jet injection device comprising:a pre-filled drug injection cartridge including: a medication cylinder having an outlet orifice, an injection nozzle, a flow path communicating the outlet orifice to said injection nozzle, a plug member in a first position sealingly disposed in said flow path, a drug-injection piston in a first position cooperating with said medication cylinder to define a variable-volume chamber of first selected size, a dose of substantially incompressible liquid medication substantially filling said variable-volume chamber at said first size with substantially no ullage volume, said drug-injection piston having a second position cooperating with said medication cylinder to define a variable-volume chamber of second selected size smaller than said first selected size, so that said incompressible liquid medication displaces said plug member from said first position of sealing disposition in said flow path to a second position of capture in said flow path, said medication cylinder and said plug member in said second position thereof cooperatively defining an open flow path between said variable-volume chamber and said injection nozzle; a hand piece assembly having a body holding said drug injection cartridge, said hand piece assembly including means for forcefully moving said drug injection piston from said second position to a third position so as to reduce the volume of said variable-volume chamber substantially ejecting said dose of liquid medication via said injection nozzle; said hand piece assembly further including a first body portion holding said drug injection cartridge, and an abutment member selectively movable into engagement with said drug injection piston to move said drug injection piston from said first position to said second position.