SYRINGE WITH DEACTIVATING MECHANISM Russian patent published in 2013 - IPC A61M5/50 A61M5/315 

FIELD: medicine.

SUBSTANCE: invention refers to medical equipment, namely syringe devices with a passive (automatic) blocking mechanism which restricts the movement of a piston rod in the distal direction after the injection to prevent reuse of the syringe. In the first version, the syringe comprises a cylinder, an elongated piston rod and a trim. The cylinder has a cylindrical side wall with an inner surface forming a chamber for retaining a fluid, an open proximal end and a distal end with a distal wall which provides a passageway for fluid into the chamber. The side wall includes a collar adjacent to the proximal end, and a transition section with a variable diameter, which extends from the collar towards the proximal end so that the cylinder diameter increases on the transition section in the direction from the collar to the proximal end. The rod has a proximal end, a distal end and a main body extending between the proximal and distal ends. The rod is movable inside the chamber in the proximal and distal directions. The proximal end of the rod comprises a pressure piece. The distal end of the rod comprises a connection section. Between the pressure piece and the main body of the piston rod, there is a flange having a diameter greater than that of the cylinder at the collar site. In addition, the rod comprises at least one breakable portion. The trim is formed with a proximal end, a distal end and a peripheral edge forming a seal with the inner surface of the cylinder and having a diameter greater than that of the cylinder at the collar site. The trim is connected to the connection section of the rod and movable relative to the connection section in the proximal and distal directions at a certain axial distance, so that when the distal end of the trim is found in contact with the distal wall of the cylinder, said flange may extend in the distal direction beyond the collar in the cylinder and block the piston rod in the cylinder to prevent reuse of the syringe. The connection section comprises a visual indicator that is fully visible until a distal initial force is applied to the piston rod. In the second version of the syringe, the cylinder chamber has a first inner diameter and it has a blocking collar adjacent to the open proximal end and having a second inner diameter smaller than the first inner diameter, a section with a greater diameter extending proximally from the blocking projection with a third inner diameter greater than the first and second inner diameters, and a transition section with a variable diameter extending between the blocking collar and the section with the greater diameter. The rod has a connection section on the distal end of the rod, and an annular projection extending radially from the rod and having an outer diameter which is greater than the second inner diameter. Also in the second version, the syringe comprises a use detection system comprising a visual indicator located on the connection section of the rod and which is fully visible until distal initial force is applied to the piston rod. In the third version, the syringe comprises a means to block the piston rod in the cylinder to prevent the syringe reuse when the distal end of the trim is found in contact with the distal wall of the cylinder, and a distal force is applied to the pressure piece; a means to detach at least a part of the piston rod from the main body when a sufficient proximal force is applied to the piston rod; an indicator to indicate that the piston rod is blocked in the cylinder.

EFFECT: invention is inactivated automatically with a mark or other indication to indicate whether the syringe is deactivated, or it is in use.

42 cl, 27 dwg