US Patent 11759117 Surgical ferromagnetic object detection system and method

A system and/or method for detecting a ferromagnetic object during surgery comprises a probe tip magnetoresistance device configured for insertion into a human or animal cavity and a probe base magnetoresistance device configured for remaining outside the cavity. The system and method detect the ferromagnetic object by comparing the electrical signals generated by the probe tip and the probe base magnetoresistance devices in response to the ambient magnetic field without generating a magnetic field to detect the ferromagnetic object.