Magnetic resonance imaging (MRI) machines have become commonplace in the medical industry. Doctors use them to diagnose life-threatening conditions, such as brain tumors and multiple sclerosis. Despite their usefulness, MRI machines are inefficient. They are huge—often filling an entire room—and incredibly expensive. Scientists at RWTH Aachen University in Germany have created a pocket-sized device that utilizes nuclear magnetic resonance (NMR) spectroscopy, the technology behind MRI machines.
The new magnet is about the size of a standard D battery and weighs just over 1 pound. Similarly sized magnets have been manufactured in the past, but, unlike others, the new NMR device is capable of making measurements as accurate as those made by much larger models.
A major problem with small magnets is inconsistency; the smaller magnets are, the more imperfections they have. These imperfections are comparable to electronic noise and can impair detection. The goal of the German scientists was to create the smallest but most homogenous magnet possible. According to an article in Technology Review, Frederico Casanova, who headed the project, said, "The important thing we did is to correct the inhomogeneity that comes from imperfections in the magnet."
The new magnet works like a miniature MRI machine (source: Frederico Casanova, RWTH Aachen University).
In their creation of the device, the scientists made modifications to the cylindrical Halbach array, a common design for magnets. Working with samarium cobalt, they placed movable rectangular pieces into the cylindrical base. They then used a computer to calculate the best positions for these pieces in order to eliminate inconsistencies.
With this current design, the magnet’s strength is only 0.7 tesla (a measurement of magnetic flux density). The researchers believe the design could be slightly modified, however, to generate 1.7 tesla. They hope to use other metals to produce an even stronger magnet.
Although massive MRI machines, which provide superb detail, are unlikely to become obsolete, tiny NMR devices could be incredibly useful in many fields. For example, doctors could use them in the office to test for local conditions like blood clots. Additionally, archaeologists and others might use these small machines to test samples in the field.
Have you had unpleasant or expensive MRI experiences? Are you in a field that might benefit from portable devices? Let us know below in the comments section!