Patent ID: 7464713

Claim:
A method for detecting a surgical implement left within a patient during surgery in an operating room, comprising the steps of: a) attaching a marker to said surgical implement before use during said surgery, said marker comprising a cavity therein and a magnetomechanical element comprising a plurality of elongated strips of magnetostrictive amorphous metal having an aspect ratio of at least about 4:1 and disposed in said cavity in a non-parallel orientation and a bias means for magnetically biasing said magnetomechanical element to arm said element to exhibit mechanical resonance at a resonant frequency in the presence of an electromagnetic interrogating field, said resonant frequency ranging from about 70 to 300 kHz, whereby said marker is provided with a signal-identifying characteristic; b) placing a surgical implement detector proximate said operating room, said detector being adapted to generate said electromagnetic interrogating field and detect said signal- identifying characteristic; c) subjecting said patient to said electromagnetic interrogating field generated by said surgical implement detector; d) detecting said signal-identifying characteristic; and e) activating an indication means in response to the detection of said signal-identifying characteristic indicative of the presence of said implement.