1. Maxima Medical Centre, De Run 46000, 5504 DB Veldhoven, The Netherlands
2. Ziekenhuis Gelderse Vallei, Willy Brandtlaan 10, 6716 RP Ede, The Netherlands
3. Mathematics and Computer Science, Eindhoven University of Technology, Building Helix, Postbus 513, 5600 MB Eindhoven, The Netherlands