Drug delivery device with cap induced needle movement

Abstract

A drug delivery device (1, 200) comprises a drug delivery unit (10, 210) comprising a housing (12, 212) extending along a general axis, a variable volume reservoir (40', 40, 140, 240), and a needle support (50', 50, 150, 250) for receiving a needle assembly (30', 30, 130, 230), the needle support (50', 50, 150, 250) and the variable volume reservoir (40', 40, 140, 240) being capable of diverging relative axial motion from a first relative position to a second relative position and converging relative axial motion from the second relative position to the first relative position; a cap (20, 120, 220) removably mountable onto the drug delivery unit (10, 210) to cover at least a portion of the needle support (50', 50, 150, 250); and a coupling mechanism configured to bring the needle support (50', 50, 150, 250) and the variable volume reservoir (40', 40, 140, 240) from the first relative position to the second relative position in response to the cap (20, 120, 220) being mounted onto the drug delivery unit (10, 210).

Description

field of invention [0001] The present invention relates to a medical device adapted to expel a drug from a reservoir through a needle. Background technique [0002] Drug delivery devices such as injection pens are widely used by persons in need of therapeutic treatment for self-administration of liquid drugs. Many injection devices are capable of repeatedly setting and injecting fixed or variable volumes of medicament by operating corresponding dose setting and injection mechanisms in the device. Some injection devices are adapted to carry pre-filled drug reservoirs containing a volume of drug sufficient to provide multiple injectable doses. When the reservoir becomes empty, the user replaces it with a new reservoir and thus can use the injection device repeatedly. Other injection devices are delivered to the user pre-filled and can only be used until the drug reservoir is emptied. Many injection devices typically expel the drug by advancing a rubber piston in a reservoir...

AI Technical Summary

Problems solved by technology

[0007] However, in addition to the high cost of the metal parts used to achieve this return, this solution also requires a complex type of device in which the drive mechanism first has to displace the entire cartridge relative to the housing during the dosing procedure, and then in the relative Displacing the piston relative to the barrel while holding the barrel in the housing

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