this invention relates to a therapeutic device and method of administering precisely measured doses of a therapeutic substance via inhalation to pediatric and adult patients . more specifically , the invention relates to a therapeutic device and method of administering inhaled medication which delivers a controlled flow rate to a mouthpiece for administration of medicament to young children and adults with a diminished capacity , at a rate of about 25 . 8 l / minute to 30 . 2 l / minute .