1. EndoCAS Center, Department of Translational Research and of New Surgical and Medical Technologies, University of Pisa, 56125 Pisa, Italy
2. Computer Science Department, Kettering University, Flint, MI 48504, USA
3. Department of Information Engineering, University of Pisa, 56122 Pisa, Italy
4. Department of Translational Research and of New Surgical and Medical Technologies, University of Pisa, 56126 Pisa, Italy
5. Center for Rehabilitative Medicine “Sport and Anatomy”, University of Pisa, 56121 Pisa, Italy