About the Authors

Erik Birgersson

chebke@nus.edu.sg

Affiliation Department of Chemical and Biomolecular Engineering, National University of Singapore, Singapore

Ee Ho Tang

Affiliation ST Dynamics, 249 Jalan Boon Lay, Singapore

Wei Liang Jerome Lee

Affiliation ST Dynamics, 249 Jalan Boon Lay, Singapore

Kwok Jiang Sak

Affiliation ST Dynamics, 249 Jalan Boon Lay, Singapore

Competing Interests

EHT, WLJL, KJS are employees ST Dynamics, whose company partly funded this study. At the time of this study, ST Dynamics is developing a product and has applied for patents for the active venting system. International Patent name "An Active Venting System and Devices Incorporating Active Venting System" (Application Number: PCT/SG2014/000498) and International Patent name "Respiratory device with unidirectional valve for attaching active venting system" (Application Number: PCT/SG2014/000228). There are no further patents, products in development or marketed products to declare. This does not alter the authors' adherence to all the PLOS ONE policies on sharing data and materials.

Author Contributions

Conceived and designed the experiments: EB EHT. Performed the experiments: EB EHT WLJL KJS. Analyzed the data: EB EHT WLJL KJS. Contributed reagents/materials/analysis tools: EB EHT WLJL KJS. Wrote the paper: EB EHT.