CONTROLLED RETRACTION SYRINGE AND PLUNGER THEREFOR

摘要

A retractable syringe (11) and plunger (20) therefore are provided, whereby the plunger comprises a controlling means (62) which facilitates control of the rate of retraction of the retractable needle. By controlling the rate of needle retraction, the likelihood of blood spattering is reduced, thereby improving the user-friendliness and appeal of the retractable syringe. Typically, the syringe is a prefilled syringe. Following plunger depression, a symmetrical ejector member (92) releases the retractable needle (40) from a retaining member (30) to thereby allow retraction of the retractable needle. Needle retraction is facilitated by a biasing means (70), such as a spring or other compressible and/or de-compressible device. The plunger comprises a plunger housing (21), in which is located the controlling means. The controlling means may be a pneumatic air space (324) inside the plunger housing which automatically acts against the retracting needle to thereby control or regulate the rate of retraction.