SELF-ASPIRATING AMPOULE FOR SUBCUTANEOUS INJECTIONS AND ASPIRATING PISTON Russian patent published in 1998 - IPC

FIELD: medical technics. SUBSTANCE: injecting liquid- containing ampoule 1 consists of cylinder 3 with wall and reciprocating piston 44 to evacuate ampoule 1 and displace injecting liquid therefrom. Piston contains embracing annular piece with vertically directed cylindrical hole and having cylindrical flat lower part, cylindrical flat upper part located at a certain distance from upper one, and side part connecting lower and upper parts and constituting a single piece with them, slope angle of the side part relative to horizontal plane being from about 1 to some 89 deg. Piston further includes embraced mushroom-shaped piece enclosing sliding cylindrical piston rod 52 and cone-shaped head on one end of the rod constituting a single piece with it and having slope angle relative to horizontal plane from about 1 to some 89 deg. Piston also has diaphragm shell 44, covering above-said embracing and embraced pieces, with cylindrical lower part and, as a single piece with it, largely cone-shaped side part, cylindrical lower part being designed to form sliding seal between embracing annular part and cylinder wall, while cone-shaped side part is appropriate to serve as diaphragm. As a result, when alternatively applying effort on rod 52 and removing the effort, deformation of diaphragm gives rise to decrease in space in the frontal part of cylinder (3) thereby displacing gas therefrom followed by restoration of original form of diaphragm resulting in aspiration effect. EFFECT: facilitated injection procedures. 10 cl, 9 dwg