Enabling Helical Needle Trajectories with Minimal Actuation: A Screw-Based Approach to Concentric Tube Needle Deployment

The clinical need for needle-based therapies capable of accessing tissues unreachable by conventional needles has motivated substantial research into steerable needles (see [1] and [2] for a review of these technologies). In particular, it has been observed that curved paths can be useful in percutaneous procedures [3]. Gilbert, et al., showed that helically pre-curved concentric tube nitinol needles can be deployed in a follow-the-leader (FTL) fashion, such that the needle shaft follows the path traced out by the tip [4]. Further information on concentric tube robots and the mechanics-based models that govern their motion can be found in [5] and [6].