Measuring brain magnetism diagnoses disease

There are various tools that clinicians use to scan brains of patients to assess whether something is malfunctioning. Techniques such as MRI or fMRI are used frequently, and work by utilizing magnetic fields. By making pictures of our insides, clinicians are able to detect anomalies, such as tumours or neurodegenerative diseases such as Alzheimer's. A new type of sensor developed by the National Institute of Standards and Technology makes measurements relying on magnetic fields a lot easier and cheaper. The small chip is sugar cube-sized and ought to make registration of brain signals easier. It can help detect diseases, but could also eventually be used to read minds.

Application
According to the scientists, the small chip can be used to detect neurodegenerative disorders by recording the magnetic field in brain areas of interest. Neurons, the cells of the brain, generate magnetic fields because they communicate with electrical signals. The small sensor detects them with incredible sensitivity, and the detected patterns tell us something about how a particular part of the brain functions.

Mechanism
The small chip is based on a cheap mechanism that relies on rubidium atoms that are locked into a small chamber. It includes a small infra-red laser and a detector that catches light. Rubidium atoms are known to absorb light, and their ability to do so increases with stronger magnetic fields. Therefore, the light signal that is detected inside the chip by the light sensor tells us something about the strength of the magnetic field in the brain.

Experiments
Tests involving human patients showed the small chip is functional, which means it may find its way into the clinic relatively soon. However, the scientists do aim to improve the sensor technology: a new version of the device should increase sensitivity by as much as ten-fold. Combined with a cheap manufacturing process, it would mean every hospital can use the small sensor for diagnostics. According to the researchers, even football teams could end up using their device, to check players for traumatic brain injury due to sports accidents, for example.

EEG
An alternative for the use of magnetic fields is simply measuring the electric signals that run through the brain. Clinicians use something called an EEG, which registers electrical pulses in the brain. Magnetic and electrical measurements are related, but the associated techniques both have their advantages and disadvantages.