Figure 4. Typical TIL values for the two surgical models SM1 and SM2 at 8 L/min (left column) and 40 L/min (right column) breathing minute volume (The symbols indicate: sealed with no leaks (•), two 3 mm leaks (○), four 3 mm leaks (▾), and six 3 mm leaks (▵). The solid vertical line corresponds to the MPPS of ∼45 nm for SM1 and ∼350 nm for SM2 models. The dashed vertical line corresponds to the mode of the challenge aerosol [75 nm]).