Patent ID: 6553326
Filing Date: 2003-04-22
Classification: A61B,G01R,G01V

Abstract:
A process for detecting distortions to probe location or orientation determinations, comprising:measuring a plurality of magnetic field values, the measured values depending on a probe's location and a probe's orientation; determining one of the probe's location and the probe's orientation from an extremum of an optimization function, the function depending on differences between the measured field values and field values from a model, determining one of the probe's location and the probe's orientation includes: guessing a location and orientation of the probe, calculating magnetic field values associated with the guessed location and orientation from a model, and evaluating a new value of the optimization function from the calculated and measured values; rejecting the guessed location and orientation in response to the new value being farther from an extremum of the function than an earlier calculated value of the function; and indicating that a distortion to the determining exists in response to the extremum belonging to a preselected range of values associated with presence of distortion.