Patent ID: 8015978
Filing Date: 2011-09-13
Classification: A61B,A61N,G01V

Abstract:
1. A system comprising: an external antenna; an external device coupled to the external antenna that generates a first waveform, drives the external antenna with the first waveform while the external antenna is moved through a three-dimensional region proximate to an implantable object a first time, periodically measures values of an electrical parameter associated with the external antenna while the external antenna is moved through the three-dimensional region the first time and driven with the first waveform, generates a second waveform that has at least one different waveform parameter than the first waveform, drives the external antenna with the second waveform while the external antenna is moved through the three-dimensional region a second time, and periodically measures values of the electrical parameter while the external antenna is moved through the three-dimensional region the second time and driven with the second waveform; and a processor that determines a first position/electrical parameter relationship based on the electrical parameter values measured while the external antenna was driven with the first waveform and positions within the three-dimensional region at which the external antenna was located when the electrical parameter values were measured, determines a second position/electrical parameter relationship based on the electrical parameter values measured while the external antenna was driven with the second waveform and positions within the three-dimensional region at which the external antenna was located when the electrical parameter values were measured, and determines first and second equations based on the first and second position/electrical parameter relationships, wherein the first equation defines a first position variable as a function of the electrical parameter and the second equation defines a second position variable as a function of the electrical parameter.