Study Status: Completed
Recruit Status: Completed
Study Type: Observational
Official Title: Airflow Perturbation Device (APD) for the Evaluation of Pulmonary and Sleep Disorders
Brief Summary: In a prospective, observational study the investigators compared resistance values measured using the airway perturbation device (APD) to impulse oscillometry and spirometry. The investigators also created reference equations for normal APD resistance ranges using the data from clinically normal volunteers.