Toward a Telescopic Steerable Robotic Needle for Minimally Invasive Tissue Biopsy

Abstract

This letter presents the design and development of a telescopic steerable robotic needle for minimally invasive tissue biopsy. Definitive diagnosis of many diseases relies on the pathological studies of small pieces of tissue extracted from human using biopsy procedures. However, traditional biopsy procedures using straight needles could miss targets, resulting in multiple insertions and enhanced injury to patients. Thus, the development of robotic needles that can steer inside soft tissue is critical to the improvement of the safety and accuracy of biopsy-based diagnosis. In this letter, a telescopic needle robot consisting of a rigid, straight outer tube and a flexible, tendon-driven inner tube is developed. By translating the tubes, pulling the tendon wire, and rotating the inner tube, the needle robot can perform follow-the-leader motion along curved trajectories in tissue and therefore preserve the integrity of tissue structures. To create a mapping from the tendon wire force to robot shape, a novel mechanic model is developed by investigating the statics of the needle-tendon assembly. Experimental studies are performed to evaluate the robot system, calibrate the mechanic model, and demonstrate the robot motion capabilities.