CA2914028A1 — Actuation mechanisms for dual chamber mixing syringes

USPTO Abstract

An automatic mixing device (200), an actuating device (100) having an integrated plunger (130) and configured to be removably mounted to the automatic mixing device (200), and a retractable syringe (10) having the automatic mixing device (200) are provided. The actuating device (100) has an initially compressed spring (150) and a trigger member (120) that is rotatable to initiate spring (150) decompression to drive depression of a mixing plunger (140) that bears against a seal (250) of the automatic mixing device (200). Another seal (260) also located in an outer chamber (240) of the mixing device (200) is capable of axial movement upon depression of the mixing plunger (140), from a first position in sealing engagement with one or more apertures (211A, B) in an inner barrel (211A, B) to a second position intermediate the apertures and vents (271, A, B, C, D) in an outer barrel (220). This allows depression of the mixing plunger (140) to force a first substance from the outer chamber (240) through the apertures (211A, B) to mix with a second substance in an inner chamber (230) of the inner barrel (210). The mixed substance in the inner chamber (230) is then delivered by the syringe (10) with subsequent needle (310) retraction.