Compensating for Torsion Windup in Steerable Needles

Document Type

Conference Proceeding

Publication Date


Digital Object Identifier (DOI)



Long, flexible, bevel-tip needles curve during insertion into tissue, and rotating the base reorients the tip to steer subsequent insertions. Friction between the tissue and the needle shaft, however, can cause a severe discrepancy between the needle base and tip angles. In this paper, I demonstrate an algorithm to properly align the entire length of the needle using torque measured at the base. My algorithm uses several intermediate base rotations to align the orientation of points along the shaft with the desired angle, with minimal remaining torque exerted by the base. I performed an experimental validation with four angle sensors attached to the needle throughout the tissue. My compensation algorithm decreased the lag throughout the needle by up to 88%.

Was this content written or created while at USF?


Citation / Publisher Attribution

2008 2nd IEEE RAS & EMBS International Conference on Biomedical Robotics and Biomechatronics, p. 936-941