1. Helsinki Institute of Information Technology, Department of Computer Science (PM,OAM,AK,SK) and Department of Information and Communication Engineering (SC), Aalto University, Finland
2. Helsinki Institute of Information Technology, Department of Computer Science (MH,OA,AK,SC) and Department of Mathematics and Statistics (JC), University of Helsinki, Finland
3. Institute of Basic Medical Sciences, University of Oslo (JC,HP) and Akershus Universitetssykehus (OT), Norway
4. Helsinki Institute of Information Technology, Department of Computer Science (PM,OAM,AK,SK) and Department of Information and Communication Engineering (SC), Aalto University, Finland samuel.kaski@aalto.fi
5. Cluster of Excellence SimTech, University of Stuttgart, Germany