Limiting life time of dispense assembly

A system comprising:

• a replaceable cartridge containing a medicament;
• and
• a drug delivery device configured to deliver at least one medicament, the drug delivery device comprising:
• a main body;
• a cartridge retainer configured to receive the replaceable cartridge of the medicament, the cartridge retainer including a hinged connection to the main body and being moveable between an open position and a closed position;
• one or more first sensors configured to detect the presence of the replaceable cartridge in the cartridge retainer, wherein the one or more first sensors are pressure activated switches;
• and
• one or more second sensors configured to detect that the cartridge retainer is in the closed position, wherein the one or more second sensors are selected from the group of sensors consisting of a light barrier sensor, a camera, a barcode reader, and a proximity sensor.

A method of detecting the presence of a cartridge of a medicament in a cartridge retainer of a drug delivery device, the method comprising:

• providing the drug delivery device including:
• a main body;
• the cartridge retainer configured to receive the cartridge of medicament, the cartridge retainer including a hinged connection to the main body and being moveable between an open position and a closed position;
• and
• a controller including:
• one or more first sensors configured to detect the presence of the cartridge in the cartridge retainer, wherein the one or more first sensors are pressure activated switches;
• and
• one or more second sensors configured to detect that the cartridge retainer is in the closed position, wherein the one or more second sensors are selected from the group of sensors consisting of a light barrier sensor, a camera, a barcode reader, and a proximity sensor;
• the controller receiving signals from the one or more first sensors and the one or more second sensors via digital inputs of the controller;
• and
• the controller determining from the received signals whether the cartridge is present in the cartridge retainer and whether the cartridge retainer is in the closed position.