Eddy current detection and compensation
First Claim
1. A method for detecting the presence of conductive objects, the method comprising:
- determining a characteristic frequency function of an undisturbed magnetic tracking system;
measuring a disturbed real-time frequency function;
calculating real and imaginary components of the position indication signal using a chi-squared minimization of the disturbed frequency function to the undisturbed frequency function;
calculating a chi-squared value based on the characteristic frequency function and the disturbed frequency function; and
monitoring the chi-squared value to detect changes indicating the presence of a conductive object.
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0 Petitions
Accused Products
Abstract
A distortion compensation method includes determining an undisturbed phase for at least one of a first position indication signal and a second position indication signal. The method includes determining an undisturbed ratio that relates the amplitude of the first position indication signal at a first frequency to the amplitude of the second position indication signal at a second frequency. The method also includes determining a disturbed amplitude of the position indication signal and adjusting a position indication based on the disturbed amplitude and phase, the undisturbed amplitude ratio, and the undisturbed phase. The method further comprises determining a relationship between the eddy current phase of the first position indication signal and the second position indication signal.
105 Citations
15 Claims
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1. A method for detecting the presence of conductive objects, the method comprising:
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determining a characteristic frequency function of an undisturbed magnetic tracking system; measuring a disturbed real-time frequency function; calculating real and imaginary components of the position indication signal using a chi-squared minimization of the disturbed frequency function to the undisturbed frequency function; calculating a chi-squared value based on the characteristic frequency function and the disturbed frequency function; and monitoring the chi-squared value to detect changes indicating the presence of a conductive object. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
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11. A system for detecting the presence of conductive objects, the system being configured to:
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determine a characteristic frequency function of an undisturbed magnetic tracking system; measure a disturbed real-time frequency function; calculate real and imaginary components of the position indication signal using a chi-squared minimization of the disturbed frequency function to the undisturbed frequency function; calculate a chi-squared value based on the characteristic frequency function and the disturbed frequency function; and monitor the chi-squared value to detect changes indicating the presence of a conductive object. - View Dependent Claims (12, 13, 14, 15)
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Specification