A team of scientists at the University of Sussex have for the first time
built a modular quantum brain scanner, and used it to record a brain signal.
This is the first time a brain signal has been detected using a modular
quantum brain sensor anywhere in the world. It's a major milestone for all
researchers working on quantum brain imaging technology because modular
sensors can be scaled up, like Lego bricks. The team have also connected two
sensors like Lego bricks, proving that whole-brain scanning using this
method is within reach—as detailed in their paper, which is published today
in pre-print. This has not been possible with the currently commercially
available quantum brain sensors from the United States.
These modular devices work like play bricks in that they can be connected
together. This opens up the potential for whole-brain scanning using quantum
technology, and potential advances for neurodegenerative diseases like
Alzheimer's.
The device, which was built at the Quantum Systems and Devices laboratory at
the university, uses ultra-sensitive quantum sensors to pick up these
tiniest of magnetic fields to see inside the brain in order to map the
neural activity.
The team applied the sensors to outside of a participant's scalp, close to
the visual cortex of the brain. They asked the participant to open and close
their eyes at 10–20 second intervals, and were able to detect a signal. This
is a very simple action, but to see it happening inside the brain—from the
outside—requires hugely sophisticated quantum technology.
Thomas Coussens Ph.D. student at the University of Sussex, who built the
sensor, explained:
"Our quantum sensor has to be exceptionally sensitive to pick up the
magnetic fields in the brain which are very weak indeed. To put it into
context, the magnetic field of a brain is a trillion times lower than that
of a fridge magnet.
"Because our device is so-far unique in that it is modular—and we've shown
the modularity works by connecting two sensors together—we now plan to scale
up this project by building more sensors to turn this into an entire brain
imaging system. This could provide significant advancements in detecting and
delivering treatment for neurodegenerative diseases such as Alzheimer's.
"This is the culmination of many months of hard work and I am thrilled to
see our first brain signal using our very own quantum sensors built entirely
by us here at the University of Sussex."
Professor Peter Krüger, Experimental Physicist and Director of the Sussex
Programme for Quantum Research at the University of Sussex explained:
"As our sensor works on a modular basis, we will now be able to scale it up
to create much more detailed images of the brain or parts of the brain. You
can't do that with the current commercial product available. This new sensor
built at the University of Sussex opens the door for UK-produced quantum
sensors, hugely important in the wider UK quantum technology landscape.
"To have this sensor is a major step to further interdisciplinary studies
involving researchers ranging from consciousness scientists and engineers to
neuroscientists which is very much in the spirit of how we tackle research
here at Sussex."
Professor Kai Bongs, Principal Investigator at the UK Quantum Technology Hub
Sensors and Timing, said:
"We are delighted with this ground-breaking development by Hub researchers
at the University of Sussex. These successes are helping considerably to
advance the UK quantum ecosystem, bringing us a step closer to exploiting
quantum sensor technology in clinical applications that will have real
societal impact. Building a strong quantum brain imaging capability in the
UK is a great example of our collaboration."
The quantum magnetic sensor uses an optically pumped magnetometer inside a
magnetic shield to reduce environmental magnetic fields and ensure they are
not being detected. In simple terms, the sensor works by putting a vapor
into a quantum state, shining a laser beam through it and using a photo
detector to see how much light has gone through. How the atomic vapor
interacts with the laser light very sensitively depends on the magnetic
field. The tiny electric currents in the neurons in the brain lead to very
small magnetic fields even outside the brain which is what the sensor picks
up.
Reference:
Modular optically-pumped magnetometer system.
arxiv.org/abs/2106.05877
arXiv:2106.05877v1 [physics.atom-ph]