1. Biomedical Diagnostics Lab (BM/d), Eindhoven University of Technology, 5612 AZ Eindhoven, The Netherlands
2. Patient Care and Measurements, Philips Research, 5656 AE Eindhoven, The Netherlands
3. Department of Anesthesiology, Intensive Care and Pain Medicine, Catharina Ziekenhuis, 5623 EJ Eindhoven, The Netherlands