1. MIRA-Institute for Biomedical Technology and Technical Medicine, Department of Biomechanical Engineering, Surgical Robotics Laboratory; University of Twente; Enschede The Netherlands
2. Department of Information Engineering and Mathematics; University of Siena, and with the Department of Advanced Robotics, Istituto Italiano di Tecnologia; Italy
3. Department of Computer Science; University of North Carolina at Chapel Hill; USA
4. Department of Biomedical Engineering; University of Groningen and University Medical Centre; Groningen The Netherlands