Patent ID: 6129668
Filing Date: 2000-10-10
Classification: A61B

Abstract:
A system for detecting a position of a magnet associated with an indwelling medical device from a measurement location on the surface of a patient, the system comprising:a housing;first, second, and third magnetic sensors supported by the housing, each of the magnetic sensors comprising sensor elements to detect magnetic field strength in three orthogonal directions, the first, second, and third magnetic sensors generating first, second, and third sets of signals, respectively, as a function of static magnetic field strength and direction due to the magnet;a processor to calculate an estimated position of the magnet in a three-dimensional space and to calculate a predicted magnetic field strength for the first, second and third sensors based on the estimated position, the processor further calculating an actual magnetic field strength using the first, second, and third sets of signals and generating an error function based on a difference between the predicted magnetic field strength and the actual magnetic field strength; anda display providing a visual display of data related to the position of the magnet in the three-dimensional space using the error function.