A bi-directional steerable catheter that, for a given tip deflection angle, generates a first articulation radius in a first lateral direction and a second articulation radius in a second lateral direction, the second articulation radius being different than the first articulation radius. The catheter includes two pull wire portions that can be individually and selectively put under tension to cause deflection of the tip in a corresponding lateral direction. Actuation of a first of the pull wire portions causes a shift in the neutral axis of the catheter over a portion of the steering section, resulting in articulation over a shorter length of the steering section and thus a smaller bend radius. Actuation of a second of the pull wire portions does not result in a neutral axis shift, so that articulation is over substantially the entire length of the steering section, resulting in a larger bend radius.
