Aerosol Deposition Characteristics in Subject-Specific Tracheobroncheal Airways

The trachea is a tubular structure which serves as the conduit which air travels to the lung. It originates just below the vocal cords, courses inferiorly into the thoracic cavity, then bifurcates into two main bronchi, each of which serve one side of lung. Those main bronchi then branch into smaller airways serving individual lobes of each side of the lung. The trachea is composed of U-shaped cartilaginous rings connected by a posterior membrane. There are several different cross-sectional shapes of the lumen of the trachea including circular, D-shaped, U-shaped, triangular, C-shaped, and elliptical [1]. In some cases, the trachea becomes flaccid and can collapse easily in the presence of positive intrathoracic pressure, which is known as tracheomalacia. This leads to airway obstruction, and may result in wheezing, stridor, and a “seal bark” cough characteristic in patient with tracheamalacia [2–4].