1. Institute of Technical Medicine (ITeM), Furtwangen University, 78054 Villingen-Schwenningen, Germany
2. Department of Mechanical Engineering, University of Canterbury, Christchurch 8041, New Zealand
3. School of Mathematics and Statistics, University of Canterbury, Christchurch 8041, New Zealand
4. Innovation Center Computer Assisted Surgery (ICCAS), University of Leipzig, 04109 Leipzig, Germany
5. Department of Microsystems Engineering, University of Freiburg, 79085 Freiburg, Germany