System for trans-dermal delivery of doses of a medicament, comprising a delivery device to be placed in dermal contact with a patient, the delivery device comprising a reservoir for holding a medicament to be delivered, a trans-dermal injection element for delivering doses of the medicament to the patient, a control unit for controlling the delivery of the medicament when activated, the system further comprising a separate hand-held drive device to be temporarily placed in proximity of the delivery device when a dose of medicament is required, the drive device comprising an activation unit for activating the control unit of the delivery device.