Patent ID: 11890450
Assignee: AMGEN INC.
Field: Medical technology (Instruments)
Classification: CPC A | IPC A

Claim 0:
1. A drug delivery device comprising:
a housing defining a shell and an inner volume;
a container at least partially disposed within the housing, the container having an inner volume adapted to contain a medicament to be administered to a user;
a drive mechanism at least partially disposed within the housing, the drive mechanism adapted to exert a force to urge the medicament out the container;
a needle assembly at least partially disposed within the housing, the needle assembly adapted to insert a needle or a trocar into the user's skin and to subsequently retract, thereby leaving a cannula within the user's skin for a period of time at least until the drive mechanism urges the medicament out the container;
a fluid flow connection coupled to the container and the needle assembly, the fluid flow connection adapted to allow the medicament to flow from the container to the needle assembly; and
a backflow prevention mechanism disposed within a coupling region between the container and the needle assembly, the backflow prevention mechanism comprising at least one flow restrictor to restrict a fluid from flowing from the cannula to the container, thereby reducing and/or eliminating clot formation during the period of time at least until the drive mechanism urges the medicament from the container to the needle assembly,
wherein the coupling region includes an upstream portion and a downstream portion, the upstream portion having an upstream diameter larger than the flow restrictor and the downstream portion having a downstream diameter smaller than the flow restrictor.