Apparatus is provided for diagnosing or treating an organ or vessel, wherein a device having at least two optical fiber sensors disposed in a distal extremity thereof is coupled to processing logic programmed to compute a multi-dimensional force vector responsive to detected changes in the optical characteristics of the optical fiber sensors arising from deflection of the distal extremity resulting from contact with the tissue of the wall of the organ or vessel. The force vector may be used to facilitate manipulation of the catheter either directly or automatically using a robotic system.
