Patent attributes
An on-body drug delivery device having a housing and a cartridge removably attachable to the housing. The cartridge comprises: a drug chamber, a piston received in the drug chamber movable from a first, initial position to a second position, an actuation device for moving the piston from the first position to the second position, and at least one breakable sterility sensor circuit formed by attachment of the cartridge to the housing, the circuit being closed when the cartridge is properly attached to the housing and broken if the cartridge is not properly attached to the housing or removed from the housing after being attached thereto, and/or the circuit being broken if the piston is not in the initial position when the cartridge is first attached to the housing.