Method and apparatus for automatic frequency selection in magnetic tracking systems

A method of automatically selecting a frequency of a magnetic field in an electromagnetic tracking system, comprising:

• generating a magnetic field from a plurality of source magnetic coils in a transmitter;
• generating magnetic sensor data by sensing the magnetic field using a plurality of sensor magnetic coils in a receiver;
• causing, by a processor, the transmitter to generate magnetic fields at a plurality of sets of frequencies;
• causing, by the processor, the receiver to sense the magnetic fields at a first one of the plurality of sets of frequencies;
• determining, by the processor, an expected amount of jitter at the first set of frequencies;
• comparing, by the processor, the expected amount of jitter at the selected set of frequencies to a measured amount of actual jitter at the first set of frequencies;
• causing, by the processor, the transmitter to generate magnetic fields at a second one of the plurality of sets of frequencies when the ratio of the measured amount of jitter to the expected amount of jitter exceeds a predetermined jitter ratio;
• and
• causing, by the processor, the receiver to sense the magnetic fields at the second one of the plurality of sets of frequencies.

A non-transitory computer readable storage medium having embodied thereon instructions for causing a computing device to execute a method of automatically selecting a frequency of a magnetic field in a magnetic tracking system in an electromagnetic tracking system, the method comprising:

• generating a magnetic field from a plurality of source magnetic coils in a transmitter;
• generating magnetic sensor data by sensing the magnetic field using a plurality of sensor magnetic coils in a receiver;
• causing, by a processor, the transmitter to generate magnetic fields at a plurality of sets of frequencies;
• causing, by the processor, the receiver to sense the magnetic fields at a first one of the plurality of sets of frequencies;
• determining, by the processor, an expected amount of jitter at the first set of frequencies;
• comparing, by the processor, the expected amount of jitter at the selected set of frequencies to a measured amount of actual jitter at the first set of frequencies;
• causing, by the processor, the transmitter to generate magnetic fields at a second one of the plurality of sets of frequencies when the ratio of the measured amount of jitter to the expected amount of jitter exceeds a predetermined jitter ratio;
• and
• causing, by the processor, the receiver to sense the magnetic fields at the second one of the plurality of sets of frequencies.