HYPODERMIC SYRINGE WITH RETRACTABLE NEEDLE

摘要

A safety needle-bearing medical advice (10) is provided. Specifically, a safety device for injecting medicinal fluid into a patient is provided. The device comprises a hollow housing (20), a needle assembly (40) and a plunger (30). The needle assembly (40) releasably retains a needle (45) in an extended position in which the sharpened tip of the needle is exposed for use. At the end of an injection stroke, the plunger (30) engages the needle assembly (40), such that the needle (45) is released and retracted into a cavity (38) within the plunger. The device (10) includes structure for reducing the dead-space volume, which represents the amount a fluid remaining in the device at the end of an injection stroke. In addition, preferably the device (10) includes structure for minimizing the volume of potential air bubbles trapped in the medicinal fluid prior to an injection.