Design of a positioning system for orienting surgical cannulae during Minimally Invasive Spine Surgery. - Iacopo Portaccio; Simona Valentini; Nevio Luigi Tagliamonte; Alessio Angiolari; Fabrizio Russo 003; Rocco Papalia; Vincenzo Denaro; Gianluca Vadala; Dino Accoto (BioRob, 2016)