1. DIANA-Lab, Dept. of Computer Science and Biomedical Informatics, University of Thessaly , Lamia , Greece
2. Hellenic Pasteur Institute , Athens 11521 , Greece
3. Dept. of Informatics and Telecommunications, National and Kapodistrian Univ. of Athens , Athens , Greece
4. Biomedical Research Foundation of the Academy of Athens , 11527 Athens , Greece
5. Department of Computer Science and Biomedical Informatics, University of Thessaly , Lamia , Greece
6. Technical University of Denmark – Department of Health Technology , Copenhagen , Denmark
7. Department of Biology, National and Kapodistrian University of Athens , 15784 Athens , Greece
8. Department of Mathematics, University of Thessaly , Greece