Electromagnetic tracking and position measurement system having interference reduction from nearby instrumentation by filtering time-division multiplexed signal via step function

A method for reducing interference caused by a magnetic tracking system, the method comprising:

• determining, by a computing device, a frequency for generating at least a portion of a magnetic field signal using a transmitter coil of a plurality of transmitter coils of a transmitter;
• configuring, by the computing device, a time-division multiplexed (TDM) control signal for controlling transmissions of the magnetic field signal from the transmitter coil, the TDM control signal configured to cause the transmitter coil to periodically transmit bursts of the magnetic field signal at the frequency at a part of a TDM cycle different from other parts of the TDM cycle for one or more other transmitter coils of the plurality;
• obtaining, by the computing device, threshold data indicating a threshold interference level for one or more devices in an environment of the magnetic tracking system;
• configuring, by the computing device, a filter for filtering the TDM control signal, the filter configured to shape each burst by filtering a step function to reduce or prevent a harmonic artifact of the bursts, at a receiver coil, resulting from causing the transmitter coil to transmit the bursts of the magnetic signal periodically based on the TDM cycle, below the threshold interference level of the threshold data;
• causing, by the computing device, the transmitter coil to generate the shaped bursts of the magnetic field signal, the generation being periodic based on the TDM cycle, wherein the magnetic field signal comprises a TDM alternating current (TDM-AC) signal;
• and
• receiving, from a sensor including a receiver coil, a sensor signal that corresponds to the magnetic field signal, the sensor including an output response indicative of a location of the sensor relative to the transmitter.

A method comprising:

• determining, by a computing device, a frequency for generating at least a portion of a magnetic field signal using a transmitter coil of a transmitter of a magnetic tracking system;
• configuring, by the computing device, a time-division multiplexed (TDM) control signal for controlling transmissions of the magnetic field signal from the transmitter coil, the TDM control signal configured to cause the transmitter coil to periodically transmit bursts of the magnetic field signal at the frequency at a part of a TDM cycle different from other parts of the TDM cycle for one or more other transmitter coils of the plurality;
• configuring, by the computing device, a filter for filtering the TDM control signal, the filter configured to shape each burst by filtering a step function to reduce or prevent a harmonic artifact of the bursts, at a receiver coil, resulting from causing the transmitter coil to transmit the bursts of the magnetic signal periodically based on the TDM cycle, wherein the magnetic field signal comprises a TDM alternating current (TDM-AC) signal;
• 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;
• causing, by the computing device, the transmitter coil to generate the shaped bursts of the magnetic field signal, the generation being periodic based on the TDM cycle;
• and
• receiving, from a sensor of the magnetic tracking system, a sensor signal that corresponds to the magnetic field signal, the sensor signal including an output response indicative of a location of the sensor relative to the transmitter.