Our researchers now will be able to listen in on our brain waves and maybe compare them to normal ones.
http://www.alphagalileo.org/ViewItem.aspx?ItemId=120619&CultureCode=en
Successful test at PTB of optical magnetometer with potential
applications in brain imaging for neurological diagnostics and in basic
research.
In future a new magnetic sensor the size of a sugar cube might
simplify the measurement of brain activity. In the magnetically shielded
room of Physikalisch-Technische Bundesanstalt (PTB) the sensor has
passed an important technical test: Spontaneous as well as stimulated
magnetic fields of the brain were detected. This demonstrates the
potential of the sensor for medical applications, such as, the
investigation of brain currents during cognitive processes with the aim
of improving neurological diagnostics. The main advantage of the new
sensor developed by NIST in the USA over the conventionally used
cryoelectronics is its room temperature operation capability making
complicated cooling obsolete. The results have recently been published
in the journal "Biomedical Optics Express".
The magnetic field sensor is called Chip-scale Atomic Magnetometer
(CSAM) as it uses miniaturized optics for measuring absorption changes
in a Rubidium gas cell caused by magnetic fields. The CSAM sensor was
developed by NIST (National Institute of Standards and Technology),
which is the national metrology institute of the USA. In this
cooperation between PTB and NIST each partner contributes his own
particular capabilities. PTB’s staff has long standing experience in
biomagnetic measurements in a unique magnetically shielded room. NIST
contributes the sensors, which are the result of a decade of dedicated
research and development.
Up to now the measurement of very weak magnetic fields was the domain
of cryoelectronic sensors, the so called superconducting quantum
interference device (SQUID). They can be considered as the „gold
standard“ for this application, but they have the disadvantage to
operate only at very low temperatures close to absolute zero. This makes
them expensive and less versatile compared to CSAMs. Even though at
present CSAMs are still less sensitive compared to SQUIDs, measurements
with a quality comparable to SQUIDs, but at lower costs, might
eventually become reality. Due to the cooling requirements, SQUIDs have
to be kept apart from the human body by a few centimeters. In contrast
to that, CSAMs can be attached closely to the human body. This increases
the signal amplitude as the magnetic field from currents inside the
human bodydecays rapidly with increasing distance.
An important application is the measurement of the magnetic field
distribution around the head, which is called magnetoencephalography
(MEG). It enables the characterization of neuronal currents. Such
investigations have gained importance during the last few years for
neurologists and neuroscientists. Objective indicators of psychiatric
disorders as well as age dependent brain diseases, are urgently needed
for the support of today’s clinical diagnostics.
Already in 2010 scientists from NIST and PTB had successfully tested
the performance of an earlier version of the present CSAM by
measurements of the magnetic field of the human heart. For the present
study the sensor was positioned about 4 mm away from the head of healthy
subjects. At the back of the head, the magnetic fields of alpha waves
were detected, a basic brain rhythm which occurs spontaneously during
relaxation. In another measurement the brain fields due to the
processing of tactile stimuli were identified. These fields are
extremely weak and the CSAM result was validated by a simultaneous MEG
measurement relying on the established SQUID technology.
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