Patent ID: 7101354

Claim:
A mixing syringe apparatus for mixing and dispensing medical fluids, said apparatus comprising: a syringe comprising a conventional hollow barrel having an elongated internal cylindrical surface, said barrel surface comprising an open proximal end and a distal end having a closed interior about an orifice through which fluid is transferred, and a stem and plunger combination, said combination being disposed to be displaced within said barrel by application of force in a predetermined direction against said stem thereby imposing predetermined differential pressures for displacing fluid within the barrel; and a removable cap which, in combination with said plunger, fully confines all fluid and material previously stored within said syringe barrel between the plunger and cap; a displaceable valved stopper disposed within said barrel between said plunger and said distal end to provide a more proximal chamber disposed between the plunger and valved stopper as a container for a first volume of matter and a more distal chamber disposed between the distal end and valved stopper as a container for a second volume of matter, said first and second volumes of matter being kept disparate before mixing and mixed by action of force directed in the predetermined direction upon the stem of the syringe; said displaceable valved stopper comprising a normally-closed valve which yields to an open state when the predetermined pressure differential is disposed across the valved stopper, the pressure differential causing diluting matter in a fluid state to be dispensed through the valve, thereby to mix the diluting fluid from the dispensing chamber with matter resident in the receiving chamber; an elastic fluid disposed within the more distal chamber for storing energy resulting from pressure derived from force applied in the predtermined direction upon the stem of the syringe, at least a portion of the stored energy effecting displacement of the valved stopper in a direction opposite direction of the applied predetermined force, once that force is terminated, thereby changing size of one chamber relative to the other chamber and providing opportunity for additional dispensing of fluid through the valve by subsequent application of force in the predetermined direction.