Reliable and Enhanced Stiffness Perception in Soft-tissue Telemanipulation

Haptic feedback is one of the missing links in robotized minimally invasive telesurgery. The teleoperation controllers are optimized so as to offer the surgeon a reliable perception of the stiffness of soft tissue, rather than following the traditional approach where tracking and force reflection fidelity are considered. The experimental results show that optimization allows for better focus on the quality of the haptic information in the performance-stability trade-off. A force sensor to measure the interaction forces with the environment is found to be indispensable for high-quality touch feedback. Next to optimization for realistic feedback of the environment stiffness, in this paper we describe how to extend human perception beyond differential thresholds and thus enhance sensitivity. Experiments on a one-dimensional system demonstrate that the operator is able to discriminate tinier differences using a telemanipulation system with enhanced sensitivity than through direct manipulation. KEY WORDS—teleoperation, force feedback