Closed-loop Planar Fuzzy Control System for a Curvature-controllable Steerable Bevel-tip Needle

Steerable needles are widely used in minimally invasive percutaneous medical procedures due to their potential advantage of enhancing targeting accuracy while avoiding obstacles. However, several factors influence the accuracy of needle tip placement, such as tissue deformation and inhomogeneity. For the accurate control of a steerable needle, several advanced control algorithms have been developed. To overcome their complicated procedures, this paper proposes a two-dimensional planar fuzzy control, which can be implemented intuitively without exhaustive mathematical derivation. The proposed algorithm is integrated with a curvature-controllable steerable bevel tip needle to follow the smooth curvilinear path. The experimental results showed that the proposed controller achieves an accurate trajectory-following capability, in which its average tracking error measured 0.043 mm and the standard deviation measured 0.11 mm.