TY - JOUR T1 - Airway obstruction is associated with reduced variability in specific parts of the tidal breathing flow–volume curve in young children JF - ERJ Open Research JO - erjor DO - 10.1183/23120541.00028-2019 VL - 5 IS - 2 SP - 00028-2019 AU - Ville-Pekka Seppä AU - Anton Hult AU - Javier Gracia-Tabuenca AU - Marita Paassilta AU - Jari Viik AU - Davor Plavec AU - Jussi Karjalainen Y1 - 2019/04/01 UR - http://openres.ersjournals.com/content/5/2/00028-2019.abstract N2 - Lung function testing in subjects with limited cooperation, such as young children, the elderly or the disabled, is often extremely challenging even when using methods that need a low level of cooperation like impulse oscillometry (IOS). Hence, measurement and analysis of tidal breathing have been studied as an alternative option for conventional lung function methods in detecting airway obstruction. However, attempts to determine clinically useful obstruction-related tidal breathing indices, such as peak points or line fits from the tidal breathing flow–volume (TBFV) curves, have produced very limited outcomes. A more recent approach has focused on looking at the tidal breathing curve variability over time. The tidal breathing indices and the mathematical methods for their quantification analysed in early studies have been diverse; for instance, approximate entropy [1, 2] and noise limit of the flow signal [3], interquartile range of various tidal breathing indices [4, 5], and coefficient of variability of tidal volume [6]. A common finding has been that lower airway obstruction is associated with reduced variability in the tidal breathing pattern.Impedance pneumography recordings during sleep at night show reduced variability in specific parts of the expiratory flow–volume curve in children with recurrent wheeze http://bit.ly/2Wkfap0 ER -