Patent ID: 8148989

Claim:
A magnetic resonance compatible apparatus configured for increasing the ability to detect ferromagnetic objects by scanning for magnetic fields produced by those ferromagnetic objects themselves and by increasing the magnetization of the objects but while not exposing the personnel associated with the ferromagnetic objects, to unsafe levels of magnetic fields, or to magnetic fields which exceed recognized safety levels, as the personnel and associated ferromagnetic objects are moved/passed through a portal the magnetic resonance apparatus including: at least one coil configured to generate a magnetic field positioned in the area of the object to be detected; an electrical energy storage capacitor bank capable of quickly releasing stored energy; a high speed, high current electronic switch capable of quickly transferring the stored energy from the capacitor bank to the coil thereby producing in the coil a short duration, single polarity magnetic field pulse; a sample and hold circuit capable of acquiring magnetic field sensor data during periods when the pulsed magnetic field is not present; and a microprocessor controller configured to control the timing and sequence of the magnetic pulse generation and the sensor data sample and hold process.