A Soft-Robotic End-Effector for Independently Actuating Endoscopic Catheters

This paper deals with the design, development, modeling, and experimental validation of a prototype endoscopic attachment that can be actuated independently by soft actuators to position an endoscopic catheter tip to a desired location. The soft actuators are miniaturized pneumatic artificial muscles (MPAMs), and by applying 137–827 kPa pressure to one or more MPAMs, the tip of the endoscopic catheter can be positioned in an approximately hemispherical region of 45 mm radius. An optimization-based forward kinematic model to predict the profile of the actuated end-effector is developed. Experiments conducted on the prototype show that the kinematics model can predict the deformation profile of the end-effector with a maximum error of 2 mm. An inverse-kinematics model to estimate the pressure required in the MPAMs to position the tip of the catheter at a specified point is also developed. The pressures in the MPAMs are controlled using an ATmel ATMega 2560 micro-controller with the inputs generated with a thumb-stick to show that real-time actuation is possible. Finally, ex-vivo experiments were conducted to show that the developed prototype end-effector can be successfully used to independently actuate endoscopic catheters.