Tactile sensing using a novel air cushion sensor: A feasibility study

This paper proposes a novel air-cushion sensor for the acquisition of tactile and force information from soft tissue, as it could be useful during robotic-assisted minimally invasive surgery in order to provide the surgeon with tactile and haptic feedback. Advancing recent work on rolling indenters [1], the sensor proposed here makes use of a rigid sphere which is held at the end of a tubular shaft and pressed against the tissue by a stream of air. Variations in tissue stiffness result in movements of the sphere within the shaft and are picked up by an optical system. The new approach allows virtually frictionless motion of the sphere across the tissue's surface and rapid acquisition of tactile information over large areas of soft tissue. The structure and working principles of this new air-cushion tactile sensor are described. Laboratory experiments are conducted to show the feasibility and illustrate the behaviour of the proposed sensor system. The outcome of the conducted experiments shows the potential of the sensor system.