Abstract: The present invention provides, in a preferred embodiment, a retractable needle (26) device for use with a syringe. The syringe may be manually driven or electronically driven. In the retracted position, the needle is enclosed within a safety shield and may be extended from the safety shield (60) upon actuation of the plunger (38) normally used to dispense the biocompatible material from the needle. In this instance, initial pressure on the plunger serves to extract the needle and after the needle is extracted, the biocompatible material is dispensed from a carpule in communication with the needle. When it is desired to retract the needle, the direction of the plunger travel is reversed thereby effectively retracting the needle back in to the safety shield.

Abstract: The syringe (10) comprises a detachable syringe barrel (14) connected to a housing (12). The housing contains a drive means connected to a plunger (24). The drive means is for extending and retracting the plunger into and out of the detachable syringe barrel. The detachable syringe barrel comprises a stopper (26) at one end thereof in sealing engagement with the interior of the barrel and for releasable engagement with the end of the plunger distal to the drive means. At least a portion of the stopper is flexible between a first position and a second position. In the first position, the flexible stopper may be disengaged from the plunger upon retraction of the plunger away from the detachable syringe barrel. In the second position, the flexible stopper is maybe engaged with the plunger upon extension of the plunger toward the detachable syringe barrel.