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

Claim 12:
13. A method of preventing backflow in a drug delivery device having a backflow prevention mechanism, the drug delivery device including housing defining a shell and an inner volume and a container at least partially disposed within the inner volume of the housing and being adapted to contain a medicament to be administered to a user, the method comprising:
at least partially disposing a drive mechanism within the housing, the drive mechanism adapted to exert a force to urge the medicament out of the container;
at least partially disposing a needle assembly 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;
coupling a fluid flow connection to the container and the needle assembly to allow the medicament to flow from the container to the needle assembly; and
disposing a backflow prevention mechanism within a coupling region between the container and the needle assembly, the backflow prevention mechanism comprising at least one flow restrictor that restricts 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.