An approach to deposition and clearance measurements in human airways.

By using the aerosol bolus inhalation technique, aerosol particles can be delivered into the airways of the human respiratory tract. For that purpose the aerosol bolus is injected near the end of a clean air inhalation. It could be shown experimentally and theoretically that the particles were only deposited in the airways. Radioactive labeled particles were deposited with this technique and clearance from the airways was determined. It could be shown that the mucociliary clearance from the airways was particle size dependent. The clearance efficiency from the airways increased with increasing particle size.