Capsule-based powder inhalers enjoy widespread use in the treatment of respiratory illnesses. Successful therapy depends not only on inhaler and active ingredient, but also on how patients use them. Inhalation at a low flow rate or for too short a time subjects the therapeutic effect to great fluctuation.

To give the patient feedback about inhalation effectiveness, scientists at the University of Bonn have developed a system from which conclusions can be drawn about inhalation quality and respirable particle quantity. The capsule rotation frequency during inhalation is used to determine airflow and inhalation duration. Rotation is read out by means of a neodymium magnet and a coil and can be used to determine such parameters as flow rate and emitted medication dose. In the future, a special app (currently in conceptual design) will enable the patient to receive the measured data easily and directly on his smartphone. He can use it to adjust his inhalation behavior, improving inhaled medication effectiveness.