Funding for this research was provided by:
Danish Working Environment Research Fund (AMFF 26-2015-09)
Received: 2 March 2020
Accepted: 20 October 2020
First Online: 31 October 2020
Ethics approval and consent to participate
: In line with the Helsinki Declaration, all participants were informed about the content of the study protocol before providing written informed consent. For the technical measurements, the information was given both written and verbally before commencement of data collection.The study was approved by the Danish National Committee on Biomedical Research Ethics (The local ethical committee of Frederiksberg and Copenhagen; H-3-2010-062) and the Danish Data Protection Agency (j.nr. 2015-41-4232). All data was de-identified and analyzed anonymously.
: There are no conflicts of interest.