The red light indicates that something is wrong, and you should contact service personnel. The yellow light indicates that there is either tension in the ropes (eg, during lifting or lowering) or that the gantry is in an extreme position, where it shouldn't be. The green light indicates that the gantry is resting safely on the claws you may place a subject under the dewar only when the green light is lit. There are four "traffic lights" behind the gantry that indicate whether or not it is safe to place a subject under the dewar. Thus it is important to understand the following process to avoid such an injury. However, when the gantry is lifted or lowered, it hangs from the ropes only, and should something unexpected happen the whole unit (~270 kg) could fall down and seriously injure someone. During measurements, the gantry rests on two claws, both of which can hold at least four times the weight of the gantry. When these buttons are pushed, the gantry is lifted or lowered by ropes that are connected to a motor outside the MSR. The gantry is lifted or lowered by pushing two buttons that are located on the back of the gantry. The gantry is usually in the sitting position, but during the helium fill on Mondays, for example, the gantry is in the lying position. The gantry can be in one of two positions, upright (sitting down) or supine (lying down). So that your equipment is not mispaced or borrowed, be sure to clearly label each item. Place experimental equipment instead in one of the cabinets outside the MSR, on the sink-side of the room. Furthermore, to prevent microscopic magnetic particles from causing spurious results, do not attach anything (eg, tape) to the Vectorview helmet.ĭo not leave any equipment in the MSR (other than screen, auditory and somatosensory stimulators, and response pads). If artefacts are seen on the raw data display, the object is magnetic and should not be brought inside the MSR.ĭo not touch Vectorview unnecessarily, and keep a respectful distance from the device. Next wave the object a few feet from the helmet, and if artefacts are not seen, then proceed to wave the object inside the helmet. First wave your bare hands inside the helmet to be sure that you yourself are not magnetic. To test an object, one member of your group should wave the object inside the closed MSR while another member watches the raw data display. (However, please only do such a test in the presence of an experienced user or one of the techs). If you do not know whether an object is magnetic or not, it is possible to test it inside the MSR. Subjects who may arrive unprepared (eg, have magnetic parts on their clothing that cannot be removed) will be issued non-magnetic clothing supplied by the hospital. When arranging for visitors or experimental subjects to come to the MEG lab, please inform them of these restrictions and see that they are appropriately prepared. Objects such as cell phones, pagers, cameras, flashlights, or any other electrical equipment are strictly forbidden. Also, to prevent any magnetic dust from getting into the MSR, always remove your shoes before entering. These include belts, keys, watches, coins, hair barrettes and pins, eyeglasses, and pieces of clothing with magnetic parts. Thus, before entering the MSR, we require that you remove any potentially magnetic objects. Because of this sensitivity, the Vectorview is placed inside a MSR.Īlthough wearing metal objects while in the MSR is not harmful to the individual, bringing magnetic objects close to the Vectorview can cause trapped flux in the SQUIDs, which can lead to a long and expensive service break which would cause an obvious delay in measurements. The sensors are ultra-sensitive in that they can pick up changes in a magnetic field in the range of femtoteslas. The Vectorview system is comprised of 306 thin-film superconducting interference devices (SQUIDs). Protecting Vectorview from Magnetic Contamination Don't use paper clips or other small metal objects (staples, etc.) around the MSR they tend to land on the floor and find their way inside the room. Anyone entering the MSR must first "de-metal" (empty pockets remove jewelry, watches, wallets, beepers, hairclips leave pens, clipboards etc. Subjects may not enter the MSR without signing a consent form. Before Entering the Magnetically Shielded Room (MSR)
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