1 Department of Paediatrics, Inselspital, Bern University Hospital, Division of Paediatric Respiratory Medicine and Allergology, University of Bern, Bern, Switzerland.
2 ARTORG Center for Biomedical Engineering Research, University of Bern, Bern, Switzerland.
3 Wal-yan Respiratory Research Centre, Telethon Kids Institute, University of Western Australia, Perth, Western Australia, Australia.