Published on in Vol 7 , No 8 (2019) :August
Preprints (earlier versions) of this paper are available at https://preprints.jmir.org/preprint/12649, first published .
1 Department of Electronics, Telecommunications and Informatics, University of Aveiro, Aveiro, PT
2 Institute of Electronics and Informatics Engineering of Aveiro, University of Aveiro, Aveiro, PT
*these authors contributed equally