Fig. 4.

Representative Y-branch model created from magnetic resonance image segmentation. We segment the inner airway wall to generate a surface model, which we project outward to create a volume model parameterized in terms of the radius R and the mucosal and submucosal thickness offsets t_m and t_s. We mesh the volume model using linear hybrid hexahedral elements with four and ten elements across the mucosal and submucosal layers.