Patent ID: 8167876

Claim:
A method comprising: causing current to flow among multiple sets of current injecting electrodes to generate a field in an organ in a patient's body, the current injecting electrodes being secured to one or more stable locations relative to the organ in the patient's body; obtaining the positions within the organ of one or more measuring electrodes used for measuring the field generated by the current injecting electrodes; in response to the current flow, measuring the field at multiple locations in the organ using the one or more measuring electrodes; modeling the field using the measurements of the field from the one or more measuring electrodes and the positions within the organ of the one or more measuring electrodes; determining expected signal measurements of the field at additional locations within the organ using the model of the field; and determining a position of one or more additional electrodes in the organ based on measurements made by the additional electrodes and the determined expected signal measurements of the field.