Abstract: The disclosure is of an improved blood gas syringe, particularly a self-filling arterial blood gas syringe. In one embodiment, the improved syringe comprises a conventional syringe barrel, a plunger rod and an elastomeric piston at the bottom of the plunger rod. The plunger rod is connected to the piston by a flexible coupling permitting the plunger rod to flex out of alignment with the piston component of the plunger without axially displacing the piston, thereby assuring that a seal is maintained between piston and syringe barrel. The syringe has several advantages over prior art blood gas syringes, such as the obviation of inadvertently drawing air into the syringe when the plunger is not kept in axial alignment therewith when being drawn back.

Abstract: The disclosure is of an improved blood gas syringe. In one embodiment, the improved syringe comprises a conventional syringe barrel, a plunger and an elastomeric piston at the bottom of the plunger. The plunger extends through and beyond the piston a short distance. The extended portion of the plunger, which is incompressible, serves as a stop means to prevent the piston from being compressed at the bottom of the barrel and to provide a chamber to hold a liquid anti-coagulant. The improved syringe has several advantages over prior art blood gas syringes, such as the obviation of inadvertently drawing air back into the syringe when pressure on the plunger is removed.