Patent ID: 6082366
Filing Date: 2000-07-04
Classification: A61B,G01V

Abstract:
An apparatus for determining a position of a marker in an organic cavity comprisingsaid marker being a magnetizable marker formed of a magnetizable material and having a marker diameter;at least one electric coil having a coil diameter of at least fivefold said marker diameter and defining a coil axis;means for applying successive current pulses through said at least one electric coil;anisotropic magnetic field sensors being arranged in axial symmetry to said coil axis and being connected in fixed relation to said at least one electric coil;means for moving said at least one electric coil and thereby said coil axis relative to the organic cavity and said marker within said organic cavity and means for detecting a position of the coil axis with relation to the organic cavity;means for detecting, storing and evaluating signals from said anisotropic magnetic field sensors; andmeans for detecting the position of said marker based on comparing successive ones of said signals from said anisotropic magnetic field sensors obtained between respective successive ones of said successive current pulses while actuating said means for moving said at least one electric coil in accordance with said comparison.