Features of haptic and tactile feedback in TORS-a comparison of available surgical systems

Sustained interest and an increase of possible indications endorse the role of robot-assisted surgery of the head and neck region. However, broad clinical application is impeded by substantial extra cost, time exposure and a supposed deficit of haptic and tactile feedback. The role of haptic feedback has barely been examined in this context, and literature provides only limited objective validation. This point of criticism applies to all commercially available systems. We created an experimental setup to evaluate, quantify and compare the performance of surgical systems. The daVinci system (Intuitive Surgical), the Flex system (Medrobotics) and standard rigid instruments (23 cm laryngoscopic grasper, Karl Storz) were compared with the human hand by head and neck surgeons (n = 15), performing a variety of surgical tasks. Specific samples with different rigidity were sorted with all devices, and the resulting orders were analyzed by permutation analysis, indicating differences in precision and accuracy of haptic and tactile feedback. The human hand was superior in all trials, acting as reference modality. The flexible instruments of the Flex system performed better than the electro-mechanically decoupled instruments of the daVinci system for the majority of measures recorded, suggesting a benefit in terms of haptic and tactile feedback in this context. While not all aspects of haptic and tactile feedback were accessible, this first objective comparison endorses the inferiority of robot-assisted surgery in terms of haptic and tactile feedback, compared to the human sense or standard surgical tools. Furthermore, the immediate force transmission of the Flex system seems to be superior to the electro-mechanical transformation of the daVinci system, indicating an advantage in terms of haptic and tactile feedback in immediate comparison. This study is providing a basis for further experiments and the development of robotic surgery towards an implementation in clinical routine.