% of puffs in this type of series Puffs duration Puffs interval
Isolated puff 9.28% 4.57 ± 2.24 s -
Serie 2-5 puffs 31.35% 4.07 ± 1.94 s 19.26 ± 15.12 s
Serie 6-15 puffs 36.68% 3.73 ± 1.77 s 16.77 ± 13.23 s
Serie>15 puffs 22.68 3.20 ± 1.61 s 13.68 ± 11.53 s
Table 1: Characteristics of puffs in series.