Patent attributes
A plurality of embodiments of mixing syringes are provided. Inventive key to all of the embodiments is a piston valve which divides a barrel to create a pair of chambers in which matter and liquid can be disparately and securely disposed before mixing. Each disclosed piston valve is actuated by force on an associated plunger rod which produces pressure within an associated syringe resulting in a change of the valve state from closed to open. In addition, each such valve comprises check valve action which is permissive to only distal flow through the syringe. Embodiments for both a basic mixing syringe and a mixing syringe with flush are disclosed. Considerations and methods for chamber filling without valve actuation are provided. A mixing syringe system with flush system utilizing a dual chamber syringe having a male luer fitting and a separate diluent containing vessel having a female luer fitting is also disclosed. In addition, a valve piston which comprises a proximally disposed skirt for providing an additional seal when the valve piston momentarily cants is disclosed. Further a valve piston, which comprises a plurality of rings, at least one of which is forced to further radially displace by a positive pressure differential applied against one of two opposing convex piston faces to thereby increase a seal between barrel wall and piston is disclosed.
