Electrode catheter positioning system

1. A system for determining a position of a catheter, the system comprising:

an electrode on the catheter;

a plurality of reference electrodes, each reference electrode of the plurality of reference electrodes configured to transmit or receive a signal to or from the electrode; and

a processor configured to;

determine a first distance between a reference electrode of the plurality of reference electrodes and the electrode as a function of an electrical characteristic based on one of the signals;

determine a second distance between the reference electrode and the electrode using an image for viewing the catheter;

determine a correlation between the first distance and the second distance; and

determine the position of the catheter as a function of the electrical characteristic or another electrical characteristic based on the signals, and the determined correlation,

wherein the plurality of reference electrodes is not positioned on or in a body surface along three mutually orthogonal axes.

2. The system of claim 1 , wherein the signals corresponding to the plurality of reference electrodes are substantially at a same frequency.

3. The system of claim 1 , wherein the electrical characteristic comprises an impedance determined by the one signal between the reference electrode of the plurality of reference electrodes and the electrode, the impedance used for determining a position of the electrode.

4. The system of claim 3 , wherein the plurality of reference electrodes comprises body surface electrodes.

5. The system of claim 4 , wherein the body surface electrodes comprise electrocardiogram electrodes.

6. The system of claim 1 , further comprising:

a first reference catheter,

wherein a first set of reference electrodes of the plurality of reference electrodes is on the first reference catheter.

7. The system of claim 6 , further comprising:

a second reference catheter,

wherein a second set of reference electrodes of the plurality of reference electrodes is on the second reference catheter.

8. The system of claim 1 , wherein the processor is configured to determine the position of the catheter using a predetermined look-up table, the predetermined look-up table including data representing distance values that correlate to data representing combinations of different impedance values.

9. A system for determining a position of a catheter, the system comprising:

a first electrode and a second electrode on the catheter;

a plurality of reference electrodes, each reference electrode of the plurality of reference electrodes configured to transmit or receive a signal to or from the first electrode and the second electrode, respectively; and

a processor configured to determine a position of the catheter as a function of a voltage potential between the second electrode and one reference electrode of the plurality of reference electrodes when the first electrode and another electrode of the plurality of reference electrodes are transmitting and receiving the signal, respectively.

10. The system of claim 9 , wherein the voltage potential is based on an electric field generated by the signal.

11. The system of claim 9 , wherein the first electrode and the second electrode are adjacent electrodes.

12. The system of claim 9 , wherein the plurality of reference electrodes comprises body surface electrodes.

13. The system of claim 9 , further comprising:

a reference catheter,

wherein the plurality of reference electrodes is on the reference catheter.