Table 1.

Scoring system employed for the ergonomic domain assessment.

Maneuvering
The accuracy of surgical maneuvers during isolation of target structures
3	Optimal perception of depth, target tissue reached with no missed movement
2	Good perception of depth with any missed movement to reach the target
1	Any intraoperative surgery-related complication
Exposure
The overall visualization of the target achieved by the adopted technology
3	Target visible and reachable
2	Target visible and reachable with minor limitations (need to change the camera or the instruments position one time per step)
1	Target visible and reachable with limitations (need to change the camera and/or instruments position two or more times per step)
Instrumentation
The easiness by which instruments could be employed simultaneously without disturbing surgical vision
3	Optimal convergence of instruments with no crowding and no need of lens cleaning
2	Moderate instrument crowding and/or need to clean the lens one time per step
1	Lack of multiple instrument convergence with fencing and/or need to clean the camera two or more times per step