Fig. 2From: An initial evaluation of the safety of a disposable oscillating positive expiratory pressure device in patients with chronic obstructive pulmonary disease: a short-term pilot studyPre- and post-study values for FEV1, FVC (% predicted), and FEV1/FVC Ratio Box-whisker plot shows mean (x), median (horizontal line), interquartile range (box), and minimum/maximum (whiskers)Back to article page