an actuator for attachment to an inhaler of the type including a pressurized canister of medicine , the actuator comprising a sensor for detecting the presence of a patient to whom medicine is to be delivered from the pressurized canister ; and the actuator comprising an electrically driven mechanical linear motion to trigger a lever which is moveable between an at rest position and an in use position in which the lever exerts a force on the canister so as to operate the inhaler and thereby release medicine from the pressurized canister to provide ease of use of the inhaler for patients with reduced or limited dexterity and grip / co - ordination . the actuator device can provide data logging using non - volatile internal memory ; the data being capable of being downloaded via physical interface or bluetooth .