An input device for a robotic catheter system includes an inner member having a generally cylindrical shape and defining an axis, and an outer member coaxially disposed on the inner member and configured to rotate about and move along the axis defined by the inner member to control a position and orientation of at least one of a catheter and a guide wire. Rotating the outer member about the axis causes the catheter, the guide wire, or both, to rotate and wherein moving the outer member along the axis causes the catheter, the guide wire, or both, to advance or retract relative to a patients body.