Birds and mammals are on extreme ends of the airflow spectrum. Mammals inhale oxygen-rich air and they exhale depleted air, exhibiting a so-called tidal flow pattern. In contrast, bird breath travels ...

The determination of airflow characteristics in the human upper airway is crucial in investigating obstructive sleep apnea, particle sedimentation, drug delivery, and many biomedical problems.

Take a deep breath in. Slowly let it out. You have just participated in one of the most profound evolutionary revolutions on Earth--breathing air on land. It's unclear how the first vertebrates ...