FIG. 2.

(a) Proposed breathing-lung system comprising the lung device, the pumping system for controlling water pressure within the device, and the reservoir for water storage. (b) PEEK tubings with three different inner diameters were used to reconstruct different breathing-lung models and breathing patterns. (c)–(e) Cross-sectional schematic view of a single deformable alveolar sac in the lung device. The black dashed line indicates the original position of the PDMS membrane. The colored solid line indicates the maximum inflation state of the alveolar sac. The colored dashed line indicates the maximum deflation state of the alveolar sac. The gray area indicates the movement area of the membrane. The arrow indicates the moving distance of the flexible membrane. The tidal volume changes of the alveolar sac in (c) restrictivelike breathing model, (d) moderate breathing model, and (e) obstructivelike breathing model. (f) The cyclic breathing pattern of the restrictivelike breathing model. (g) The cyclic breathing pattern of the moderate breathing model. (h) The cyclic breathing pattern of the obstructivelike breathing model. The red dashed box indicates the breathing profile of one breathing cycle.