Electromagnetic position measurement system with sensor parasitic loop compensation

A magnetic tracking system, comprising:

• a magnetic tracking device comprising:
• a sensor configured to generate a sensor electromotive force (EMF) that measures a magnetic field that is generated by a magnetic field transmitter;
• a mechanism configured to select between a first operating mode in which the sensor generates the sensor EMF when receiving the magnetic field and a second operating mode in which the sensor generates a reduced sensor EMF when receiving the magnetic field;
• and
• an interconnecting circuit configured generate a parasitic EMF in each of the first operating mode and the second operating mode when receiving the magnetic field;
• a processing device connected to the magnetic tracking device by the interconnected circuit, the processing device configured to:
• receive a first measurement for the first operating mode, the first measurement representing the sensor EMF and the parasitic EMF;
• receive a second measurement for the second operating mode, the second measurement representing the parasitic EMF and the reduced sensor EMF;
• compare the first measurement and the second measurement;
• and
• based on comparing the first measurement and the second measurement, determine an approximate value of the sensor EMF,
• wherein the mechanism comprises a diode in parallel with the sensor, the diode configured to be reverse biased in the first operating mode and configured to be forward biased in the second operating mode.

A magnetic tracking device comprising:

• a sensor configured to generate a sensor electromotive force (EMF) that measures a magnetic field that is generated by a magnetic field transmitter;
• a mechanism configured to adjust a sensitivity of the sensor between a higher EMF state of the sensor EMF and a lower EMF state of the sensor EMF;
• an interconnecting circuit configured generate a parasitic EMF when receiving the magnetic field;
• wherein the interconnecting circuit is configured to connect to a processing device, the processing device configured to:
• receive a first measurement representing the higher EMF state of the sensor EMF and the parasitic EMF;
• receive a second measurement representing the lower EMF state of the sensor EMF and the parasitic EMF;
• compare the first measurement and the second measurement;
• and
• based on comparing the first measurement and the second measurement, determine an approximate value of the sensor EMF,
• wherein the mechanism comprises a diode in parallel with the sensor, the diode configured to be reverse biased in a first operating mode and configured to be forward biased in a second operating mode.