Patent ID: 6484118
Filing Date: 2002-11-19
Classification: A61B,G01B,H01F

Abstract:
A system for determining the position of a medical device having a sensor, said system comprising:a plurality of field radiators, each field radiator having a plurality of radiator elements, each radiator element generating an electromagnetic field distinct from one another through simultaneous energizing of said radiator elements; a signal processor operatively connected to said field radiators and said sensor of said medical device, said signal processor receiving a sensing signal from said sensor indicative of the electromagnetic field sensed at said sensor, said sensing signal defining a measured electromagnetic field at said sensor, said signal processor also having a desired range of accuracy for said system stored therein, said signal processor including: (a) an initial position estimator for establishing an initial position estimate for said sensor; (b) a magnetic field calculator for calculating the electromagnetic field at said initial position estimate; (c) a steepest descent calculator for calculating a steepest descent of said calculated electromagnetic field to said measured electromagnetic field; and (d) a new position estimate calculator for calculating a new position estimate of said sensor based on said steepest descent; wherein said signal processor determines said position of said sensor when said new position estimate of said sensor is within said desired range of accuracy.