Granted Patent B2

US 12,616,390 · App. 18/960,984 · Granted May 5, 2026

Inventors: Westley S. Ashe (Hinesburg, VT); William Petrow (Charlotte, VT)

Assignee: Northern Digital Inc.

A61B5/062A61B34/20A61B2034/2051

Abstract

Claims (35)

1 . A system for tracking and position measurement comprising:

a transmitter configured to generate a magnetic field signal;

a receiver configured to generate a signal representing an output response indicative of a location of the receiver relative to the transmitter based on the magnetic field signal generated by the transmitter; and

a computing device in communication with the transmitter and the receiver, the computing device configured to:

configure a control signal for controlling transmissions of the magnetic field signal from the transmitter, the control signal causing the transmitter to periodically transmit bursts of the magnetic field signal;

configure a filter for filtering the control signal to prepare each burst for transmitting at the transmitter, each prepared burst reducing or preventing a harmonic artifact of the respective burst at the receiver;

cause the transmitter to periodically generate the prepared bursts of the magnetic field signal, the generation based on the control signal; and

receive, from the receiver, the signal representing the output response indicative of the location of the receiver relative to the transmitter,

wherein the filter comprises a windowing filter that prepares a burst by reducing a rate of change of an excitation signal applied to the magnetic field signal, and wherein the filter is configured based on a determined threshold or based on a determined signal strength of a harmonic artifact for the magnetic field signal transmitted by the transmitter.

2 . The system of claim 1 , wherein the receiver comprises a core for a receiver coil of the receiver, the core having a relative magnetic permeability value greater than 1.

3 . The system of claim 2 , wherein the core comprises one of a ferrite material or a permalloy material.

4 . The system of claim 1 , wherein a coil of the transmitter is configured to generate a magnetic field signal at a frequency value that is different from other magnetic field signals at other frequencies, the other magnetic signals being generated by other coils of the transmitter.

5 . The system of claim 4 , wherein each burst is prepared by applying a filter signal that prevents interference of the magnetic field signal of a coil with adjacent measurement modalities of other coils.

6 . The system of claim 1 , wherein the filter is configured to reduce the harmonic artifact received at another electronic device in an environment to below a threshold level specified for the electronic device.

7 . The system of claim 1 , wherein the receiver is part of a sensor is selected from a group comprising: a hall-effect sensor, a magnetoresistive sensor, a magneto-optical sensor, and a fluxgate magnetometer.

8 . The system of claim 1 , wherein the computing device is further configured to:

determine a parameter value representing a magnetic property of a receiver core of the receiver; and

configure the filter for filtering the control signal based on the parameter value for the receiver core of the receiver.

9 . The system of claim 1 , wherein configuring the filter for filtering the control signal comprises adjusting a size of a signal envelope based on the determined threshold or the signal strength of the particular harmonic artifact for the magnetic field signal transmitted by the transmitter.

10 . A method for tracking and position measurement comprising:

configuring, by a computing device, a control signal for controlling transmissions of a magnetic field signal from a transmitter of a magnetic tracking system, the control signal configured to cause the transmitter to periodically transmit bursts of the magnetic field signal;

configuring, by the computing device, a filter for filtering the control signal to prepare each burst for transmitting at the transmitter, each prepared burst reducing or preventing a harmonic artifact of the respective burst at a receiver;

causing, by the computing device, the transmitter to periodically generate the prepared bursts of the magnetic field signal, the generation based on the control signal; and

receiving, at the computing device via a receiver of the magnetic tracking system, a signal representing an output response indicative of a location of the receiver relative to the transmitter; and

wherein the filter comprises a windowing filter that prepares a burst by reducing a rate of change of an excitation signal applied to the magnetic field signal, and wherein the filter is configured based on a determined threshold or based on a determined signal strength of a harmonic artifact for the magnetic field signal transmitted by the transmitter.

11 . The method of claim 10 , further comprising:

obtaining, by the computing device, threshold data from one or more other devices after a first transmission of the magnetic tracking system; and

in response to obtaining the threshold data, configuring, by the computing device, the filter to prepare each burst for a second transmission.

12 . The method of claim 10 , wherein a receiver coil of the receiver comprises a core that has a relative magnetic permeability value greater than 1.

13 . The method of claim 12 , wherein the core comprises one of a ferrite material or a permalloy material.

14 . The method of claim 10 , wherein the receiver is part of a sensor selected from a group comprising: a hall-effect sensor, a magnetoresistive sensor, a magneto-optical sensor, and a fluxgate magnetometer.

15 . The method of claim 10 , wherein the computing device is further configured to:

determine a parameter value representing a magnetic property of a receiver core of a receiver coil; and

configure the filter for filtering the control signal based on the parameter value for the receiver core of the receiver coil.

16 . The method of claim 10 , wherein configuring the filter for filtering the control signal comprises adjusting a size of a signal envelope based on the determined threshold or the signal strength of the particular harmonic artifact for the magnetic field signal transmitted by the transmitter.

Assignments (2)

Continuity (3)

References Cited (61)