comment on this article

Miniature sensor measures magnetic activity in human brain

Miniature sensor measures magnetic activity in human brain

A miniature atom based magnetic sensor developed by the National Institute of Standards and Technology (NIST) has been used to measure alpha waves in the brain associated with a person opening and closing their eyes, as well as signals resulting from stimulation of the hand.

The sensor could be used for biomedical applications such as studying mental processes and advancing the understanding of neurological diseases.

Measurements were compared with the signals recorded by a SQUID (superconducting quantum interference device) – the world's most sensitive commercially available magnetometer. Although currently less sensitive, the NIST sensor is said to have the potential for comparable performance while offering potential advantages in size, portability and cost.

The study indicated that the mini sensor could be useful in magnetoencephalography (MEG), a procedure that measures the magnetic fields produced by electrical activity in the brain. MEG is used for research on perceptual and cognitive processes in healthy subjects as well as screening of visual perception in newborns and mapping brain activity prior to surgery to remove tumours or treat epilepsy.

MEG currently relies on SQUID arrays mounted in heavy helmet shaped flasks containing cryogenic coolants. The NIST sensor is about the size of a sugar cube, and unlike SQUIDs, can operate at room temperature, so it could enable lightweight and flexible MEG helmets. It would also be less expensive to mass produce than typical atomic magnetometers.

"We're focusing on making the sensors small, getting them close to the signal source, and making them manufacturable and ultimately low in cost," said NIST co author Svenja Knappe. "By making an inexpensive system you could have one in every hospital to test for traumatic brain injuries and one for every football team."

The mini sensor consists of a container of about 100billion rubidium atoms in a gas, a low power infrared laser and fibre optics for detecting the light signals that register magnetic field strength by absorbing light.

In testing the mini sensor measured magnetic signals of about 1 picotesla (trillionths of a tesla). Scientists expect to boost its performance by increasing the amount of light detected. Calculations suggest it could soon match the sensitivity of SQUIDs.

Author
Simon Fogg

Comment on this article


Websites

http://www.nist.gov

Companies

NIST

This material is protected by MA Business copyright See Terms and Conditions. One-off usage is permitted but bulk copying is not. For multiple copies contact the sales team.

What you think about this article:


Add your comments

Name
 
Email
 
Comments
 

Your comments/feedback may be edited prior to publishing. Not all entries will be published.
Please view our Terms and Conditions before leaving a comment.

Related Articles

Data driven defence

The defence industry is facing stagnating or tightening budgets in many of its ...

Analogue power module

Intersil has launched the first 42V single-channel DC/DC step-down power module ...

EEE Conference

The date for the 2017 Electrical and Electronic Equipment and the Environment ...

Custom MMIC design

Plextek RFI CEO Liam Devlin discusses the technical and commercial ...

Finding its voice

The National Physical Laboratory (NPL) is the UK’s National Measurement ...

The big build

It’s fair to say that politicians, with a few noticeable exceptions, have never ...

A man with a plan

Cypress Semiconductor was formed in 1982 and went public in 1986. Until 2016, ...