Medical device navigation tracking

A surgical method for a patient, the surgical method comprising:

• inserting at least a distal portion of a surgical device into a body orifice of the patient, the surgical device having an inertial measurement unit configured to produce an inertial signal as a function of the movement of the device body, the inertial measurement unit comprising a magnetometer and an inertial sensor;
• producing a stationary magnetic field at a fixed and prescribed location relative to the patient, the prescribed location being a sterile field having the patient;
• detecting, by the magnetometer, the stationary magnetic field;
• determining the location of at least a portion of the surgical device as a function of the inertial signal and the stationary magnetic field;
• automatically zeroing out the inertial measurement unit during use as a function of the information relating to the prescribed location;
• forwarding a position signal having positional information relating to the surgical device.

A surgical system comprising:

• a device having a movable device body and configured to produce a first inertial signal as a function of the movement of the device body;
• a first inertial measurement unit supported by the device body and configured to produce a first inertial signal as a function of the movement of the device body, the first inertial measurement unit being prone to first drift;
• a second inertial measurement unit supported by the unit and configured to produce a second inertial signal as a function of the movement of the device body, the second inertial measurement unit being prone to second drift, the first inertial measurement unit being in a known position relative to the second inertial measurement unit;
• and
• a controlling unit configured to subtract the first inertial signal from the second inertial signal to detect at least some of the first drift and second drift and to determine the location of at least a portion of the device body,
• the controlling unit comprising an output to transmit a position signal having positional information relating to the movable device body.