Evaluating the benefit of contact-force feedback in robotic surgery using the Saroa surgical system: A preclinical study.

Introduction: Robotic surgery without contact-force feedback could be less safe, as forces exerted by the robot system may exceed tissue tolerance. This study aimed to evaluate the benefit of contact-force feedback.

Methods: Nine junior and 11 senior surgeons performed two tasks using Saroa, a robotic surgical system with a force feedback function. In Task A, the participants estimated the order of stiffness of substances when feedback was on and off. In Task B, the effect of feedback on compression with a designated force (3 N) was assessed.

Results: In Task A, the proportion of participants who correctly estimated the order of stiffness of the substances was similar when feedback was on and off. However, the median maximum force applied to the substances was significantly smaller when feedback was on than when it was off (5.0 vs. 6.9 N, p = .011), which was more obvious among the junior surgeons (5.0 vs. 7.7 N, p = .015) than among the senior surgeons (4.7 vs. 5.9 N, p = .288). In Task B, deviations from the designated force (3 N) for three substances were smaller when feedback was on (0, -0.1, and 0.7, respectively) than when it was off (-0.3, -0.5, and 1.3, respectively). Regarding the dispersion of the force to the substances, the interquartile range tended to be smaller with feedback; this trend was more obvious in the junior surgeons.

Conclusion: With contact-force feedback, tissue stiffness could be estimated with a small force, particularly by the junior surgeons; specified force could be accurately applied to the tissue.