A dry powder inhaler consisting of a first chamber having an orifice for holding a dry powder and a gas, and a second chamber directly connected to the first chamber by at least one passageway for receiving an aerosolized form of the dry powder from the first chamber and delivering the aerosolized dry powder to a user. A pressure sensor monitors the pressure in the second chamber. A vibrator coupled to the first chamber aerosolizes the dry powder and cause the aerosolized powder to move through the passageway whereby to deliver the dry powder from the first chamber to the second chamber as an aerosolized dry powder. A vibrator control unit controls operation of the vibrator based on the monitored pressure in the second chamber and a dosing scheme in which the dosing time is determined by the volume of each inhalation.
