Device for locating endocardial electrodes

A device for locating a moveable electrode used in endocardial treatment, comprising:

• a moveable electrode that can be positioned to contact a plurality of locations on an endocardial surface;
• a positioning electrode defining a triaxial system of spatial coordinates, the positioning electrode capable of being positioned inside a subject's heart without enclosing the moveable electrode;
• a polarization circuit that applies an electrical signal to the moveable electrode and the positioning electrode;
• a detector connected to the moveable electrode and to the positioning electrode that detects a potential established between the moveable and the positioning electrode as a result of the application of the electrical signal;
• and
• a measuring circuit sensitive to the potential, the measuring circuit determining, on the basis of the detected potential, a position of the moveable electrode relative to the system of spatial coordinates defined by the positioning electrode such that a characteristic of the endocardial surface can be electronically formed from a sequence of position measurements with the moveable electrode contacting the endocardial surface at a plurality of locations.

A method of locating a probe electrode comprising:

• providing a probe assembly including a positioning electrode array defining a geometric body;
• contacting a tissue surface at a first location with a probe comprising a probe body and a probe electrode;
• inserting the probe assembly into a body;
• deploying the positioning electrode array within the body such that the probe is located outside the geometric body;
• applying an electrical signal to the probe electrode and the positioning electrode;
• detecting a positioning signal in response to the applied signal;
• determining a position of the probe electrode with the positioning signal;
• and
• repositioning the probe electrode to contact the tissue surface at a second location and repeating the applying, detecting and determining steps to generate an electronic representation of the tissue surface.