Patent ID: 7580739

Claim:
A system comprising: a device that is swallowed, passes though a subject, and includes a constant magnetic field generator generating a constant magnetic field; and a position transducer that includes at least first, second, and third magnetic detectors each detecting an intensity of the magnetic field, a calibration magnetic field generator, disposed at a fixed relative position to the subject, and generating a calibration magnetic field for position calibration of at least one of the first, second and third magnetic detectors, a coordinate calibrating unit calibrating a position coordinate of the at least one of the first, second and third magnetic detectors using an intensity of the calibration magnetic field detected by the at least one of the first, second and third magnetic detectors, and a position processor calculating a position of the device in the subject based on the intensity of the constant magnetic field detected by at least the first, second and third magnetic detectors and based on at least the position coordinates of the first, second and third magnetic detectors after the calibration of the position coordinate of the at least one of the first, second and third magnetic detectors by the coordinate calibrating unit.