Accurate dose control mechanisms and drug delivery syringes

摘要

A dose control mechanism for a syringe includes a plunger having a coarse pitch screw on its exterior surface, a housing having a corresponding coarse pitch guide along the interior surface of the housing, a screw having a fine pitch screw which interfaces with a fine pitch nut of an adapter, wherein the plunger has an internal annular space within which screw at least partially resides. An accurate dose drug delivery syringe includes such a dose control mechanism, a barrel, a plunger seal, and a barrel adapter assembly having a barrel tip and a needle. The syringe may be a fill-at-time-of-use syringe, a pre-filled syringe, or a safety syringe having integrated needle retraction or needle sheathing safety features, or a combination thereof. Methods of assembly, manufacturing, and operation are similarly disclosed.

主权项

1. A dose control mechanism for a syringe comprising:
a housing having an interior surface including a course pitch guide; a plunger having an exterior surface and an internal annular space, the internal annular surface including a first key aspect, the exterior surface including a coarse pitch screw, the plunger residing at least partially within the housing, the coarse pitch guide along the interior surface of the housing interfacing with the course pitch screw of the plunger; and a screw having a second key aspect and a fine pitch screw which interfaces with a fine pitch nut of an adapter; wherein the screw at least partially resides in the internal annular space of the plunger, the first key aspect of the plunger and the second key aspect of the screw being directly engaged such that rotational movement of the plunger directly causes rotational movement of the screw.