Magnets in the application of medicine:
Pigeon enthusiasts know that if you fly pigeons hundreds of of kilometers away, they will automatically return to the nest. Why do pigeons have such a good ability to recognize the family? It turns out that pigeons are sensitive to the Earth's magnetic field, and they can use the changes in the Earth's magnetic field to find their home. If a magnet is tied to the head of a pigeon, the dove will get lost.
If pigeons fly over radio towers, powerful electromagnetic interference can also cause them to lose their way. In medicine, the use of nuclear magnetic resonance to diagnose the body of abnormal tissue, to determine disease, this is our more familiar with the magnetic resonance imaging technology, the basic principle is as follows: The nucleus is positively charged and spins. Normally, the arrangement of the nucleus spin axis is irregular, but when it is placed in an external magnetic field, the nuclear spin space orientation transitions from disorder to order. The magnetization vector of the spin system increases gradually from 0, and when the system reaches the equilibrium, the magnetization strength reaches the stable value. If the nuclear spin system at this time by the external role, such as a certain frequency of RF excitation nucleus can cause resonance effect. After the RF pulse stops, the nucleus, which has been intensified by the spin system, cannot maintain this state and will revert to the original arrangement in the magnetic field, releasing a faint energy, becoming a radio signal, checking out the many signals and making them spatially distinguishable, and getting the images of the nuclei in motion. NMR is characterized by the flow of liquid does not produce signals called flow effect or flow gap effect. So the blood vessels are gray-white tubular structures, and the blood is black without signal. This makes the blood vessels very easy to separate soft tissue.
Normal spinal cord Surrounded by cerebrospinal fluid, cerebrospinal fluid is black, and a white hard film for fat foil, so that the spinal cord displayed as a strong white signal structure. MRI has been applied to the imaging diagnosis of all systemic systems. The best effect is craniocerebral, and its spinal cord, heart big blood vessel, joint skeleton, soft tissue and pelvic cavity and so on. It is not only possible to observe the anatomical changes of the various chambers, large vessels and valves in cardiovascular disease, moreover, it can be used for ventricular analysis, qualitative and semi-quantitative diagnosis, can be used for multiple sections, high spatial resolution, showing the whole picture of heart and lesion, and its relationship with the surrounding structure, superior to other X-ray imaging, two-dimensional ultrasound, radionuclide and CT examination. Magnetism can not only diagnose, but also help to treat diseases. The magnet is the ancient Chinese medicine blindly medicinal herbs. People use the magnetic differences in different components of the blood to separate red and white cells. In addition, the magnetic field and the human meridian interaction can achieve magnetic therapy, in the treatment of a variety of diseases have a unique role, has a magnetic pillow, magnetic belt and other applications. The separator made of magnets can remove the iron at the end of the flour and so on, magnetized water can prevent the boiler scaling, magnetized seeds to some extent, to increase crop production.