Soft Morphing Interface for Tactile Feedback in Remote Palpation

Teleoperated systems are routinely used in robotic surgery but have not yet permeated other medical procedures, such as palpation. The main obstacle preventing it is the absence of tactile feedback. Commercial devices solely rely on visual feedback, and haptic feedback has been shown possible by the scientific literature, but tactile feedback is largely absent. One of the challenges of such feedback is the complexity of the actuating mechanism. The most advanced devices are able to mimic remote environments by using a large number of rigid linear actuators, showcasing complex and voluminous designs. We propose a soft morphing feedback interface, entirely made using silicone to resemble human soft tissues. We also aim to demonstrate how such a device can be easily integrated into a teleoperated system for remote palpation. Firstly, we describe the design methodology and the manufacturing that allows having a compact and functional device. Then, we investigate the system's tactile channel's delay. Finally, we test its spatial accuracy while palpating rigid objects of different shapes and abdomen-like soft phantoms with and without abnormalities. Overall, we showcase that our solution can be used effectively to deliver tactile feedback, with up to 88% accuracy, whilst being entirely soft and compact.