1. Life Supporting Technologies, E.T.S.I. Telecomunicación, Universidad Politécnica de Madrid, Avenida Complutense 30, Madrid, Spain. E-mails: dsalvi@lst.tfo.upm.es, jmontalva@lst.tfo.upm.es, mta@lst.tfo.upm.es
2. AIT Austrian Institute of Technology GmbH, Health & Environment Department, Biomedical Systems, Donau-City-Str. 1, 1220 Vienna, Austria. E-mails: barbara.prazak-aram@ait.ac.at, christopher.mayer@ait.ac.at