| abstract |
The dual chamber syringe is employed for collecting blood samples. The syringe includes a plunger which is connected to a first piston which, in turn, is connected via a string to a second piston. A passageway is formed in the wall of the syringe barrel to communicate the duct at the forward end of the barrel with the chamber between the two pistons. Thus, upon withdrawal of the plunger from a barrel, fluid flows into the chamber created between the two pistons. Subsequent movement of the two pistons in unison causes a whole blood sample to be drawn into the foremost chamber within the barrel. The syringe can be subsequently connected with a vacutainer via a needle assembly so as to discharge the whole blood sample into the vacutainer for subsequent testing procedures. The discard fluid can be separately dispensed into another container. A catch is employed on the syringe barrel or on the plunger to positively prevent a movement of the plunger into the barrel which would cause a discharge of the discard fluid. |