Graphitic nanofibers, which include tubular fullerenes, nanotubes and fibrils, which are functionalized by chemical substitution, are used as electrodes in electrochemical capacitors. The member is securable along a portion of the member to a secondary member and is functionally operational such that one end of the member is movable from a first position out of contact with a media path into a second position in contact with the media path. The spatial position of an ablation catheter or other device with respect to the imaging plane is more accurately determined, allowing a physician to identify specific anatomy in the relative location of a catheter or catheters.