Multi-sensory force/deformation cues for stiffness characterization in soft-tissue palpation

In the commercially available robot-assisted surgical systems, camera vision constitutes the only flow of data from the patient side to the surgeon side. This paper studies how various modalities for feedback of interaction between a surgical tool and soft tissue can improve the efficiency of a typical surgical task. Utilizing a haptics-enabled master-slave test-bed for minimally invasive surgery, user performance during a telemanipulated soft tissue stiffness discrimination task is compared under visual, haptic, graphical, and graphical plus haptic feedback modes in terms of task success rate and completion time and the amount of energy transfer and consequently trauma to tissue. While no significant difference is found in terms of the task completion times, graphical cueing and visual cueing are found to lead to the highest success rate and the highest risk of tissue damage (proportional to energy), respectively