IOP Institute of Physics

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For the development of detection systems that can identify tiny fluctuations in large magnetic fields caused by ferromagnetic moving objects. The portable technology is being used to ensure the safe use of MRI scanners and to detect contraband in prisons.

Under the strong magnetic attraction of an MRI scanner, ferromagnetic objects such as scissors or medical gas cylinders can become dangerous projectiles; while medical implants such as pacemakers, brain stimulators and shunt valves can have their functions severely affected, leading to patient harm.

Metrasens’ ferromagnetic detection systems (FMDS) can sensitively detect tiny fluctuations in large ambient magnetic fields caused by ferromagnetic moving objects and so can detect the presence of "risk items" before they approach the MRI scanner. The system factors out unwanted magnetic influences – which can be caused, e.g., by traffic – and uses secondary optical sensors to determine whether people are in the immediate vicinity of the sensors, ensuring that alarms are only set off in potentially dangerous circumstances.

In prisons, the technology is being used successfully for contraband detection. FMDS have superior detection performance for mobile phones and can be used anywhere within a prison, in contrast to conventional metal detectors and X-ray technologies. The use of FMDS has been recommended by both health and security organisations such as the American College of Radiology and the National Offender Management Service.

The company

The Metrasens team in Malvern are world leaders in ferromagnetic detection and now provide MRI safety solutions globally through expert local distributors. As a result, the company has seen a strong consistent annual revenue growth since being founded in 2005.

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