Method and apparatus of to detect metal fragment in patients

Abstract

A detector to detect metal fragments (especially in pre MRI scanning) comprising: a first loop of conducting material, means to feed an rf signal to the first loop, a second loop of conducting material, and means to detect an induced rf signal consequent to said rf signal in said first loop, said second loop being geometrically symmetrically arranged with said first loop such that the rf signal, induced is therein is substantially zero when there are no metal fragments in the close proximity of the sensor. Preferably the second loop comprises two halves arranged in anti-phase, such in the form of a figure of eight. The loops are arranged to be substantially co-planar, such as on a PCB.

Dependencies are inferred from the claim text.