System for determining the position of a medical device within a body

A patch electrode for use in determining a position of a medical device disposed within a body within a three-dimensional coordinate system, the patch electrode comprising:

• a flexible base layer configured for attachment to a first external surface of the body;
• a first electrode supported on the base layer and configured to establish an electrical pathway with another electrode disposed on a second external surface of the body opposite the first external surface and to generate an electric field within the body;
• a second electrode supported on the base layer, the second electrode configured to establish an origin of the coordinate system and to generate a reference signal against which a signal generated by a position sensor on the medical device is compared;
• and
• wherein the patch electrode is configured to support a position sensor comprising a coil.

A patch electrode for use in determining a position of a medical device disposed within a body within a three-dimensional coordinate system, the patch electrode comprising:

• a flexible base layer configured for attachment to a first external surface of the body;
• a first electrode supported on the base layer and configured to establish an electrical pathway with another electrode disposed on a second external surface of the body opposite the first external surface and to generate an electric field within the body;
• and
• a position sensor comprising a coil coupled to the flexible base layer.