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US 11,439,317 B2Granted
Position determination system and method
AssigneeMedtronic Navigation, Inc.
InventorsShai Ronen, Andrew Bzostek, Brad Jacobsen, Andrew Wald
Life of this patent
Estimating the term…
Abstract
Disclosed is a method to remove distortion from a navigation system. The navigation system may be used to perform a procedure on a subject. The procedure may be any appropriate procedure. The navigation system may be used to account for the distortive effects of various conductive objects positioned near the subject on which the procedure is performed.
Claims21
A system to track a member in a volume, comprising:
- a transmitter operable to generate an electro-magnetic field at a plurality of frequencies;
- a tracking device having at least a first sensor configured to sense the field at each frequency of the plurality of frequencies;
- a transmission system to transmit a signal regarding the sensed field at each of the frequencies;
- a processor system configured to:
- receive the signal,
- evaluate the received signal to determine if an interference is present,
- if an interference is determined to be present (i) evaluate a model of a flux including two or more circuits, (ii) determine a distortion free flux based on the modeled flux extrapolated to zero frequency, and (iii) output the determined distortion free flux, and
- determine a position of the tracking device based on a distortion free field determined based on the determined distortion free flux.
5 more elements
A method of tracking a member in a volume, comprising:
- receiving a signal from a sensor regarding at least one field component of a field in a navigation volume;
- operating a processor system to:
- evaluate a model including a first circuit parameter and a second circuit parameter,
- extrapolate the model to estimate the at least one field component at a zero frequency,
- output the estimated at least one field component at the zero frequency, and
- determine a position of the tracking device based on the estimated at least one field component at the zero frequency;
- wherein evaluate a model including the first circuit parameter and the second circuit parameter, includes:
- further operating the processor to recall from a memory system a set of instructions to:
- evaluate a measured magnetic field flux at a first frequency of a plurality of frequencies as a model of a first resistor-inductor (R-L) circuit;
- evaluate the measured magnetic field flux at the first frequency of the plurality of frequencies as a model of a second resistor-inductor (R-L) circuit.
7 more elements
A method of tracking a member in a volume, comprising:
- operating a transmitter to transmit an undistorted field at a plurality of frequencies;
- allowing an interfering object to interfere with the undistorted field to form a distorted field;
- receiving a signal from a sensor at a position in a navigation volume regarding the distorted field at the position in the navigation volume, wherein the signal includes information regarding the distorted field in the navigation volume;
- operating a processor system to:
- evaluate a model including a first circuit parameter and a second circuit parameter,
- extrapolate the model to estimate a flux at a zero frequency at the position,
- output the extrapolated flux at the zero frequency, and
- determine the position of the tracking device based on the flux at the zero frequency;
- and
- operating a display device to display the determined position;
- wherein the flux at the zero frequency is substantially the sensed flux at the position in the undistorted field.
8 more elements
Dependencies are inferred from the claim text.