SYRINGE WITH COLLAPSIBLE PLUNGER TIP

摘要

A blood collection syringe of the present invention minimizes contact of the blood during and after collection with extraneous gases. In a preferred embodiment of a syringe (20) of the present invention, a plunger tip (22) is mounted on a plunger (40) positioned in a syringe barrel (24). The plunger tip (22) includes a hollow sealing member (42) having leading (44) and trailing members (52) with a resilient wall (60) extending therebetween. An interior chamber is defined by the wall (60), the leading (44), and trailing members (52). Circumferential sealing rings extend from the leading and trailing member for sealing engagement with the syringe barrel. At least one slit (66) is formed in and extends through the leading member. When the plunger (40) is fully extended into the syringe barrel (24), the resilient wall (60) collapses so that the leading (44) and trailing members (52) of the plunger tip (22) become positioned near each other at the head of the syringe barrel and the volume of the interior chamber is minimized.