The magnetic technology that I have decided to talk about is the MRI, or Magnetic Resonance Imaging. This machine has helped fix injuries and even save lives by being able to see and create detailed images of inside the human body that cannot be seen from the outside. It helps doctors examine internal body structures and can detect many problems, including spinal damage, tumours, strokes, eye and ear problems and can also be used to measure brain structure and function. Another key use of the MRI is to detect early cancer signs. This has saved countless lives and has been a breakthrough on the cancer-fighting front.
An MRI machine is found inside a hospital and is shaped like a cylinder. You lie down onto a stretcher and get inserted into the doughnut-shaped machine. Scans usually last 30 to 60 minutes and require the patient to lie perfectly still. Another version has been invented, called the open MRI machine. This was invented for claustrophobic people, who did not like the tight space or the loud clanging of the machine. The MRI was invented by Raymond Damadian, who was an American medical practitioner and physician. He was born in 1936 and successfully did the first full body scan on a patient in 1977. He was partly inspired to make this by the fact that his grandmother died of breast cancer when he was ten.
Magnets and magnetic fields
What are magnets and how do they work? Magnets are objects that are able to produce a magnetic field. Magnets are commonly made from iron, but can also be made from nickel, cobalt, and loadstone. Magnetism is the force exerted when they attract or repel each other. As you might have noticed, many things are not magnetic, like cloth, paper, gold, and wood. Magnetism is caused by where things called “domains” point to. A more complicated way to say this is talk about atoms and their electrons.
Atoms make up everything in the universe. Atoms have things called electrons, which carry electric charges. These electrons spin around the core of the atom, and this generates an electrical current, which causes it to become a tiny magnet. Most objects domains are pointing in different directions, or when electrons are spinning in different directions. This makes weak magnetic materials like paper. But when the majority of the domains are pointing in the same direction and electrons are spinning the same way, this creates strong magnetic substances like iron. If you put an iron nail inside a magnetic field, ALL the domains will line up, and the iron nail will become a magnet. However, as soon as you take the nail out of the magnetic field, its magnetic powers will cease to exist. Magnets have 2 poles, the north pole and the south pole. If you press the north and south pole together, they will attract each other. If you put the north and north or south and south pole together, they will repel each other. If you cut a magnet in half, you just get 2 smaller magnets.
Magnetic fields
A magnetic field is the area of affect around the magnet, or how far its field of control reaches. The closer the lines are together, the more affect the magnet has. The same thing applies when the magnetic lines are more spread out, the less affect the magnet has. Magnetic field lines are invisible, but you can see them with iron filings. The iron filings are spread out around the magnet, and resemble magnetic field lines. In this diagram you can see that the closer you get to the magnet, the less spread out the lines are. You can also see that the iron filings are very heavily concentrated around the poles of the magnet. This shows that the poles of the magnet have the strongest pull. The direction in which the lines travel is always from the south pole to the north pole. How does the MRI use magnets to function? The MRI uses extremely strong magnets to work. These magnets work with radiofrequency pusles to create signals from your body.
