Syringe with means for allowing passage of air while preventing the passage of blood to obtain a gas-free blood sample

摘要

A syringe device for obtaining a gas-free blood sample has a tubular body connected to an hypodermic needle. The tubular body receives a resilient sealing member operatively connected to a plunger rod. The sealing member and plunger rod have a vent formed longitudinally therealong to provide a passageway for the purge of air as an interior chamber of the tubular body is filled with blood. The passageway is covered with an hydrophobic filter allowing the passage of air until such time as blood completely contacts the filter, at which time blood cannot cross the hydrophobic filter. The interior chamber containing the blood sample is then purged of all air.