Patent ID: 7789862

Claim:
A multi-chamber syringe apparatus for sequentially dispensing medical fluids from a proximal and a distal chamber of the syringe, said apparatus comprising: a barrel of a conventional medical syringe having a hollow cylindrical wall having an internal surface which is concentrically disposed about an elongated medial axis, said barrel surface comprising an open proximal end and a distal end having a closed interior about an orifice through which fluid is transferred; a plunger rod and plunger tip combination disposed to be displaced within said barrel by application of a directional force against said plunger rod for dislocating fluid thereby; a discharge assembly comprising a stopper which, when disposed within said barrel between said plunger combination and said distal end, provides a proximal chamber between the discharge assembly and plunger tip and a disparate distal chamber between the discharge assembly and said closed interior surface; said proximal chamber comprising space for fluid which comprises a volume of gas which does not exceed a predetermined volume, filling only a portion of the chamber thereby, and a volume of liquid which fills space in the proximal chamber not taken by the gas; said discharge assembly stopper comprising a normally closed valve having a part which effects opening of the valve by being displaced proximally relative to the rest of the discharge assembly, said part being so displaced upon collision with the distal end of the syringe and as a consequence of accelerating compressive forces between the wall and the discharge assembly stopper; said discharge assembly stopper further comprising structure which provides access to a liquid zone which is void of the gas within the proximal chamber; and said discharge assembly stopper structure further comprising a hollow, proximally-extending conduit sleeve, wherethrough liquid flows from the proximal chamber through the normally closed valve, once opened, and an associated conduit sleeve access portal disposed within the liquid zone whereby only liquid flows into the conduit sleeve and, therefore, from the proximal chamber when dispensing fluid from the proximal chamber subsequent to dispensing fluid from the distal chamber and the predetermined volume of gas is retained within the proximal chamber.