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Workspace and pivot point for robot-assisted endoscope guidance in functional endonasal sinus surgery (FESS)
Klaus Wolfgang Eichhorn1, Ralf Westphal, Carsten Last
1Department of Otorhinolaryngology, University Hospital Bonn, Bonn, Germany.
Background:
For the further development of robot-assisted endoscope guidance in functional endoscopic sinus surgery (FESS), ground data about the workspaces and endoscope movements in conventional FESS are needed.
Methods:
Applying a self-developed marker-based tracking system, we collected the pose data (position and orientation) of the endoscope and all other instruments used in five real sinus surgeries.
Results:
The automated segmentation of the endoscope poses shows the shape of a hourglass, with a pivot region or pivot point at the 'waistline' of the hourglass, close to the nasal entrance in the nasal dome.
Conclusion:
We were able to identify a pivot point at the waistline of the segmented endoscope poses. The size of the pivot point corresponds with the diameter of the 4 mm endoscope. Because of the reduction to four degrees of freedom for endoscope motions (three rotations and one translation), easier and safer robot-assisted endoscope guidance becomes feasible.

