1. PGS Research, Halfway Green, Walton‐on‐Thames, Surrey KT12 1RS, United Kingdom.
2. TNO‐TPD, P.O. Box 155, 2600 AD Delft, The Netherlands.
3. Philips Medical Systems, P.O. Box 10.000, 5680 DA Best, The Netherlands.
4. Delft University of Technology, Faculty of Applied Sciences, P.O. Box 5046, 2600 GA Delft, The Netherlands.