NEEDLE RETRACTION SYSTEM

摘要

A retractable needle medical assembly includes a barrel and a plunger assembly defining an internal passageway within which a retraction member is mounted. The retraction member is biased into the passageway, by means of a spring or a vacuum located within the passageway. The medical assembly further includes a needle assembly consisting of a needle mounted to a hub. The hub is releasably engaged with the barrel. In one embodiment, an automatic retraction system is provided for engaging the retraction member with the hub upon movement of the plunger assembly toward the hub, and automatically releasing engagement between the hub and the barrel. Final movement of the plunger assembly toward the needle assembly disengages a retaining ring which retains the retraction member in position at the end of the passageway. The retraction member and needle assembly are then drawn into the passageway, to enclose the end of the needle to prevent accidental contact therewith and subsequent reuse of the medical assembly. The invention further contemplates a manual actuator system disposed between the needle hub and the barrel, for releasing engagement therebetween upon manual actuation by the user to result in withdrawal of the retraction member and needle into the passageway. The needle retraction system may be incorporated into a medical device such as a syringe, or into a blood collection system.