Method for detection and compensation of eddy currents
CA 2756830 C · Owner: Northern Digital Inc. · Inventors: Nieminen, John M.; Kirsch, Stefan R.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A method and system for detecting the presence of conductive objects are provided. The method includes determining a characteristic frequency function of an undisturbed magnetic tracking system and measuring a disturbed real-time frequency function. Real and imaginary components of a position indication signal are calculated using a chi-squared minimization of the disturbed frequency function to the undisturbed frequency function. A chi-squared value based on the characteristic frequency function and the disturbed frequency function is calculated and the chi--squared value is monitored to detect changes indicating the presence of a conductive object.
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Listed from its CIPO record in Patent Yard's archive of Canadian patents past their term. Its claims, description and drawings are in the CIPO record and on Google Patents, and the Claude kit works from them.
Why it's free to use
- Filed April 19, 2004 and granted July 7, 2015. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended April 19, 2024.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by April 19, 2026.
- We check Canadian rights only. A patent in its family in another country could still be in force: check its family on Google Patents.
Timeline
Timeline From CIPO dates
Sources & verification
Official CIPO records
Everything on this page comes from the CIPO record linked above. Contains information licensed under the Open Government Licence – Canada.