Sabrina S. Falloon, PhD, University College London, London, UK.
Shabira Abbas, PhD, SCA Hygiene Products AB, Gothenburg, Sweden.
Chatrine Stridfeldt, MSc, SCA Hygiene Products AB, Gothenburg, Sweden.
Alan Cottenden, PhD, University College London, London, UK.
Correspondence: Sabrina S. Falloon, PhD, care of Alan Cottenden, Department of Medical Physics and Biomedical Engineering, University College London, Gower St, London WC1E 6BT, UK ([email protected]).
This work was funded by SCA Hygiene Products AB, Gothenburg, Sweden, and 2 of the authors (Shabira S. Abbas and Chatrine Stridfeldt) are SCA employees.There are no other conflicts of interest.