An instrument driver operable to control catheter instruments. First and second carriages are movably coupled to a frame of an instrument driver. Each carriage is configured to support a catheter instrument. The first and second carriages are independently rotatable about a longitudinal axis of the respective first and second catheter instruments and rotatable independently of an instrument driver frame. Independent carriage control provides for the carriages being independently movable in at least three different directions with at least two different types of motion.
