APPARAT TIL BLODPROEVETAGNING

摘要

A needle assembly for facilitating the collection of a blood sample from a patient into an evacuated collection container while alleviating the danger of flow of fluid from the collection container into the patient during and after collection of the blood sample. The assembly includes a housing, a forward penetrating end for insertion into the patient, a rearward end for coupling with an evacuated collection container, a continuous passageway therethrough, and a resilient elastomeric valve member on the assembly normally in position to close the passageway between the patient and the rearward end and adapted to be responsive to a predetermined decrease in pressure in the rearward end to deform and automatically open the passageway when an evacuated container is coupled with the rearward end. Thereafter, the valve is responsive to a predetermined increase in pressure in the rearward end of the assembly to automatically return to the closed position and prevent flow of fluid from the rear end of the assembly to the patient.