The invention provides an inhalation device using an electrically driven vibratory element (14) for releasing a drug dose into a flow channel (10) , and a controller (26) for activating/deactivating the vibratory element. A sensor arrangement (18 ,22) is able to differentiate between inhalation flow and exhalation flow through the flow channel , to assist in forming a model of the breathing pattern of the user. The device can detect reliably inhalation flow patterns from patients of all ages.