1. A system for releasing an aerosol for inspiration by a patient comprising: a flow sensor for measuring a patient's breath flow in a non-linear flow path, at least a portion of said non-linear flow path being incorporated in a disposable unit, means, including a look-up table Or an algorithm stored in a memory, for controlling flow of the selected medication in said non-linear flow path by compensating for non-linearity in said non-linear flow path; a reservoir of a selected medication having thereon an electric circuit element identifying the selected medication, said reservoir being incorporated in said disposable unit; a valve for releasing the selected medication from said reservoir, thereby to form an aerosol; means for actuating the valve to release a controlled amount of the selected medication; means responsive to the electronic circuit element for obtaining the identity of the selected medication; means for containing the operating parameters for administering controlled amounts of the selected medication; and means for controlling the actuating means to release a controlled amount of the selected medication in accordance with the operating parameters associated with the identified selected medication.