Abstract
Purpose Design a compact, ergonomic, and safe endoscope positioner dedicated to the sino-nasal tract, and the anterior and middle-stage skull base. Methods A motion and force analysis of the surgeon's movement was performed on cadaver heads to gather objective data for specification purposes. An experimental comparative study was then performed with three different kinematics, again on cadaver heads, in order to define the best architecture satisfying the motion and force requirements. Results We quantified the maximal forces applied on the endoscope when traversing the sino-nasal tract in order to evaluate the forces that the robot should be able to overcome. We also quantified the minimal forces that should not be exceeded in order to avoid damaging vital structures. We showed that the entrance point of the endoscope into the nostril could not be considered, as in laparoscopic surgery, as a fixed point but rather as a fixed region whose location and dimensions depend on the targeted sinus. Conclusion From the safety and ergonomic points of view, the best solution would be a co-manipulated standard 6-degree of freedom robot to which is attached a gimbal-like passive remote manipulator holding the endoscope.