1 KTH Royal Institute of Technology, School of Engineering Sciences in Chemistry, Biotechnology and Health, Department of Biomedical Engineering and Health Systems, Division of Ergonomics, Hälsovägen 11C, 141 57, Huddinge, Sweden. Electronic address: ansg@kth.se.
2 KTH Royal Institute of Technology, School of Engineering Sciences in Chemistry, Biotechnology and Health, Department of Biomedical Engineering and Health Systems, Division of Ergonomics, Hälsovägen 11C, 141 57, Huddinge, Sweden.