Design of a Miniaturized Actuation System for Robotic Lumbar Discectomy Tools

In this paper, we present the design of a miniaturized actuation system for robotic lumbar discectomy tools. Lumbar dis-cectomy is one of the most common types of back surgery in the United States. Our previous work proposed a new robotic lumbar discectomy (RLD) system consisting of teleoperated articulated instruments inside a robotic cannula for performing this operation. The robotic cannula is used for the independent translation and rotation of the instruments residing in it. Due to the large servo-motor based actuation systems of the initially developed instruments, it was not possible to achieve a fully integrated RLD system. Here, we present the design of a shape memory alloy actuation system for teleoperating RLD tools that allows full integration with the robotic cannula. More than a 10X size reduction in footprint has been achieved. Experimental results show that SMA-driven actuation system meets the instrument range-of-motion, manipulation, and grasping force requirements. Integrated system tests demonstrate the successful operation of the miniaturized RDL tools with the robotic cannula.