METHODS FOR IMPROVING STABILITY OF CONCENTRIC TUBE STEERABLE DEVICES USING ASYMMETRIC FLEXURAL RIGIDITY

A concentric tube steerable device includes a plurality of tubes having a nested, concentric configuration. The tubes include an outer tube and an inner tube that extends coaxially within the outer tube. The inner tube terminates at a tip, and a pose of the tip is effectuated through individual or collective rotation or translation of the tubes about a tube axis. The concentric tube steerable device includes an actuator for rotating at least one tube about a respective tube axis, and a translator for translating at least one tube along a respective tube axis. Each tube includes a precurved portion and a corresponding axis of precurvature. For at least one tube, a flexural rigidity of the tube along its axis of precurvature is less than a flexural rigidity of the tube along a second axis that is perpendicular to the axis of precurvature, thereby improving stability of the tube.