Design and Evaluation of Bidirectional Continuous Rotation and Variable Curvature Needle Steering Algorithm

Abstract

The success rate of robotic-assisted needle-guided interventions for applications such as tissue biopsy and targeted drug delivery relies heavily on the accuracy of the needle placement. Tissue shift and needle tip deflection due to needle-tissue interaction are some factors that can adversely affect the outcome of these procedures. In this paper, we present a novel algorithm for robotically-steered bevel tip needles that provides variable needle curvatures by continuously controlling the rotation speed of the needle in a bidirectional manner. Our algorithm is an extension of the Continuous Rotation and Variable Curvature (CURV) algorithm and extends its use with wired sensorized needles. Additionally, we present algorithms for the implementation of our proposed method for closed-loop needle steering in robotic systems with image or sensor feedback. To validate our approach, we perform two benchtop needle insertion experiments in a gelatin phantom and ex vivo tissue. In the first experiment, we demonstrate the capability of our proposed algorithm in achieving variable curvatures and compare it with the CURV algorithm and our simulation results. The second experiment studies the effect of the unidirectional and bidirectional needle steering on the tissue wind-up using a novel force collection setup. Our results highlight the capability of the proposed algorithm in achieving variable curvature profiles and suggest a potential advantage compared to the original method in terms of reducing the imbalanced forces sensed at the load cell due to the needle-tissue friction buildup.