Needle Steering Controller Design for Flexible Steerable Needle Utilizing Robust Backstepping Control Strategy

In Minimal Invasive Surgery (MIS), steerable flexible needles are commonly utilized as surgical tools to improve target-reaching accuracy. Nevertheless, challenges like tissue deformation, tissue inhomogeneity, and noisy sensory measurements can lead to inaccuracies in needle-tip positioning within the tissue domain. Therefore, to ensure precise needle placement in tissue region, designing a robust non-linear closed-loop needle steering control becomes a crucial aspect in percutaneous intervention procedures. Consequently, in pursuit of accurate and precise needle placement within tissue, various controller methodologies are evident in current literature. However, to address the complexity associated with the design of existing control strategies, this study introduces a robust non-linear needle steering controller within the tissue environment, with the goal of stabilizing the needle within a designated plane. Our proposed needle steering technique incorporates the backstepping based controller that involves the splitting of entire needle kinematic model into several smaller designs while ensuring closed-loop stability through Lyapunov stability analyses. Efficacy of the devised needle steering approach is validated by comparing it with existing control techniques through extensive simulation studies, specifically focusing on needle placement in both 2D and 3D planes. Furthermore, experimental validation is performed involving brachytherapy needle with both artificial tissue phantom and biological tissue.