PRE-FILLED SAFETY DILUENT INJECTOR

摘要

A safety needle-bearing device (10, 110, 210, 310) for mixing and injecting medication from a two-chambered cartridge (50, 150, 250, 350) is provided. The device includes a needle (12, 112, 212, 312) that extends through the forward end of a barrel (30, 130, 230, 330). The two-chambered cartridge (50, 150, 250, 350) is attached to the barrel (30, 130, 230, 330) and contains components of a medication stored separately in the chambers. A plunger (40, 140, 240) in the rearward end of the cartridge can be advanced into the cartridge to combine the separate components and prepare the medication. As the cartridge (50, 150, 250, 350) is advanced forwardly into the barrel (30, 130, 230, 330), the medication is injected through the needle (12, 112, 212, 312) and into a patient. At the completion of the injection stroke, the cartridge (50, 150, 250, 350) engages a needle retainer to actuate needle retraction. The needle is subsequently retracted to shield the contaminated needle.