A manipulable portion of a catheter system advances out of a lumen of a catheter sheath at a distal end of a shaft, which is also within the lumen of the catheter sheath. The catheter system causes different advancement and retraction trajectories of a manipulable portion out of and into the lumen based at least upon different relative movements between the catheter sheath and the shaft. A projection and a corresponding receiver may be used to control relative positioning of the catheter sheath and the shaft, as well as to control positioning of the manipulable portion. The catheter system may control metering rates of a control element coupled to the manipulable portion during advancement and retraction of the manipulable portion. A control element of the catheter system has varying amounts of length outside a distal end of the catheter sheath during advancement and retraction of the manipulable portion.
