I. Introduction
Over the past decade or so, researchers have begun to link measurements in respiratory sounds to diseases as varied as asthma, obstructive sleep apnea, respiratory infections, swelling, malformations and tumors [1]–[8]. Consequently, there is a growing interest to better understand the underlying mechanisms that produce these sounds in both health and disease. Modeling of the acoustic properties of the respiratory system allows the anatomic and pathologic links to be investigated in detail through comparisons between model predictions and acoustic measurements performed under various physiologic and clinical conditions.