System and apparatus for ferromagnetically screening prone patients

摘要

A ferromagnetic detection apparatus (FMDS) 100 for screening a prone patient (possibly prior to an MRI exam) comprises: a first magnetic sensor 104 in a housing 102, the sensor measuring an ambient magnetic field or gradient within a detection volume and producing a corresponding measurement signal; signal processing means for electronically filtering the sensor signal to produce a detection signal indicative of a magnetic object moving through the detection zone; a detector 106 for examining the detection signal to determine the presence or absence of a ferromagnetic object in the detection zone; and a warning device 108 for emitting an alert when a ferromagnetic object is determined to be present. The housing is connected to a support mechanism 114, 116 enabling it to be movably positionable in at least a direction with a substantially vertical component, in use. A method comprises locating a patient on a non-ferromagnetic gurney 112, configuring a ferromagnetic screening apparatus horizontally and adjusting its height so the patient may pass closely beneath, moving the gurney beneath the screening apparatus, and observing the response of the apparatus.