Assessing new technologies: patient-device interactions and deposition.

As our understanding of aerosol therapy matures, advances in technology afford the potential for solving the major problems in clinical aerosol delivery: control of variability in dosing, and targeting of therapy to different regions of the lung. As "interactive" devices are developed, testing on the bench becomes more sophisticated and demanding. The present review begins with simple in vitro testing techniques and addresses their ability to predict in vivo deposition. Advances in technology are reviewed and control of delivery in vivo is demonstrated.