Method and system for position orientation correction in navigation

A medical navigation system, comprising:

• a transmitter configured to emit electromagnetic (EM) fields in response to current at one or more frequencies;
• first and second EM sensors each configured to detect the EM fields emitted by the transmitter and to generate a signal representative of each detected EM field;
• and
• a computerized navigation system comprising:
• one or more tangible, non-transitory, machine-readable media collectively storing instructions executable by a processor to:
• drive the transmitter at one or more frequencies to generate one or more EM fields, wherein the one or more frequencies are sufficiently low such that the one or more EM fields are frequency independent;
• measure one or more signals generated by the first EM sensor in response to detecting the one or more EM fields, respectively;
• measure one or more signals generated by the second EM sensor in response to detecting the one or more EM fields, respectively;
• and
• calculate a distortion in at least one of the one or more signals generated by the first EM sensor and the one or more signals generated by the second EM sensor based at least on a distance between the first and second EM sensors, a change in the one or more signals generated by the first EM sensor and the one or more signals generated by the second EM sensor, and the frequency response of the EM sensors when driven at a frequency of approximately zero.

One or more tangible, non-transitory, machine-readable media collectively storing instructions executable by a processor to:

• drive a transmitter at one or more frequencies to generate one or more EM fields, wherein the one or more frequencies are sufficiently low such that the one or more EM fields are frequency independent;
• measure one or more signals generated by a first EM sensor in response to detecting the one or more EM fields, respectively;
• measure one or more signals generated by a second EM sensor in response to detecting the one or more EM fields, respectively;
• and
• calculate a distortion in at least one of the one or more signals generated by the first EM sensor and the one or more signals generated by the second EM sensor based at least on a distance between the first EM sensor and the second EM sensor, a change in the one or more signals generated by the first EM sensor and the one or more signals generated by the second EM sensor, and the frequency response of the first EM sensor and the second EM sensor when driven at a frequency of approximately zero.