Patent ID: 7778689
Filing Date: 2010-08-17
Classification: A61B

Abstract:
1. A method for locating a medical instrument introduced into a body of an examination object, comprising: arranging at least four electrodes at the body of the examination object; recording a three-dimensional image data of a body region of the examination object by an imaging medical examination device; determining an electrical conductivity model of the examination object as a function of the three-dimensional image data; determining an electric field distribution, including a respective location of a plurality of equipotential surfaces having a constant voltage, of the examination object as a function of the electrical conductivity model and spatial positions of the electrodes based on a voltage being applied for at least three different electrode pairs formed from the four electrodes which do not all lay in one plane; applying the voltage at each of the three electrode pairs respectively; determining three voltage values at an electrode of the medical instrument for the applied voltage at each of the three electrode pairs respectively; determining a spatial position of the medical instrument as a point of an intersection of the equipotential surfaces assigned to the three voltage values at the electrode of the medical instrument; and wherein more than three voltage values are determined at the electrode of the medical instrument, the spatial position of the medical instrument is determined by averaging the voltage values from the equipotential surfaces.