Patent ID: 8260395

Claim:
A system for mapping data and positioning an instrument in a three dimensional volume, comprising: a first drive patch and a second drive patch; a driving unit interconnected with the first and the second drive patches operable to generate a parameter between the first and the second drive patches; an instrument having a body covering and an electrode extendable from a retracted position to an extended position through an exit opening of the body covering, wherein the electrode is operable to both move relative to the first drive patch and the second drive patch and sense the parameter generated by the driving unit; a cover operably associated with the electrode; a memory system operable to store a data point representing a position in space relative to the first and the second drive patches; a processor operable to execute instructions to determine a position of the electrode relative to the stored data point; and a display device operable to display an icon representing a virtual representation of a position of the electrode; wherein the body covering includes a portal positioned a distance from the exit opening; wherein the portal is operable to allow an electrolyte to contact the electrode when the electrode is in the retracted position; wherein the cover is operable to move with the electrode to cover the portal in the body covering to substantially eliminate access to the electrode of the body covering through the portal once the electrode is in the extended position through said exit opening.