Patent ID: 8728034

Claim:
A method for delivering fluid, the method comprising: providing a fluid delivery device having a reusable part that includes a motor and one or more gears and a disposable part that includes: a reservoir containing the fluid; a plunger configured to displace the fluid into and out of the reservoir, wherein the plunger is connected to a drive screw; and an engagement member configured to engage with the drive screw, wherein prior to connection of the reusable part and the disposable part, the engagement member is disengaged from the drive screw allowing the drive screw to freely move within the engagement member; positioning a free end of the drive screw within a receiving portion in the reusable part; and connecting the reusable part with the disposable part, wherein, upon connection, the engagement member engages with the drive screw such that upon rotation of the engagement member, the drive screw and the plunger are linearly displaced to deliver fluid contained with the reservoir.