Abstract: A device for administering a fluid medicament by injection comprises a dosing portion (1) with a collapsible reservoir (10). The reservoir (10) has a maximum volume in an extended state and a minimum volume in a collapsed state. Prior to injection, the reservoir (10) is in the extended state and contains a liquid to be administered, and the reservoir (10) is biased towards the collapsed state. The device further comprises a needle (2), wherein a lumen (20) of the needle (2) is in fluid communication with the reservoir (10). The device further comprises a shield portion (3) with a plug (30). Prior to injection, the shield portion (3) is in a deployed position where the plug (30) blocks the lumen (20) of the needle (2). The shield portion (3) is adapted to move in response to an actuation force from the deployed position to a retracted position where the lumen (20) of the needle (2) is open, thereby causing the reservoir (10) to shift to the collapsed state to expel the liquid through the needle.

Abstract: A control method uses in a membrane filter system operated in iterative filtration cycles, the cycles including a production period and a following flushing. A setting of a crossflow on the entrance side (4) of a membrane (2) in the production period is controlled such that the energy consumption (E) per filtration cycle reaches an optimum. A corresponding membrane filter system is provided.