Two years ago, patient T6 volunteered for the BrainGate
clinical trials and had a 100-channel electrode array implanted into
the left side of her brain in regions responsible for movement. So if your motor cortex is dead like mine this would need to be implanted in the premotor cortex, which is also mostly dead in my case. Then you have to move to the executive control area, good luck with that.
For patient T6, 2014 was a happy year.
That was the year she learned to control a Nexus tablet with her
brain waves, and literally took her life quality from 1980s DOS to
modern era Android OS.
A brunette lady in her early 50s, patient T6 suffers from amyotrophic
lateral sclerosis (also known as Lou Gehrig’s disease), which causes
progressive motor neuron damage. Mostly paralyzed from the neck down, T6
retains her sharp wit, love for red lipstick and miraculous green
thumb. What she didn’t have, until recently, was the ability to
communicate with the outside world.
Brain-Machine Interfaces
Like T6, millions of people worldwide have severe paralysis from
spinal cord injury, stroke or neurodegenerative diseases, which
precludes their ability to speak, write or otherwise communicate their
thoughts and intentions to their loved ones.

The
field of brain-machine interfaces blossomed nearly two decades ago in
an effort to develop assistive devices to help these “locked-in” people.
And the results have been fantastic: eye- or head-tracking devices have
allowed eye movement to act as an output system to control mouse
cursors on computer screens. In some cases, the user could also perform
the click function by staring intently at a single spot, known in the
field as “dwell time.”
Yet despite a deluge of promising devices, eye-tracking remains
imprecise and terribly tiring to the users’ eyes. Since most systems
require custom hardware, this jacks up the price of admission, limiting
current technology to a lucky select few.
“We really wanted to move these assisted technologies towards
clinical feasibility,” said Dr. Paul Nuyujukian, a neuroengineer and
physician from Stanford University, in a talk at the
2015 Society for Neuroscience annual conference that took place this week in Chicago.
That’s where the idea of neural prostheses came in, Nuyujukian said.
In contrast to eye-trackers, neural prostheses directly interface the
brain with computers, in essence cutting out the middleman — the
sensory organs that we normally use to interact with our environment.
Instead, a baby-aspirin-sized microarray chip is directly implanted
into the brain, and neural signals associated with intent can be decoded
by sophisticated algorithms in real time and used to control mouse
cursors.
It’s a technology that’s leaps and bounds from eye-trackers, but still prohibitively expensive and hard to use.
Nuyujukian’s team, together with patient T6, set out to tackle this problem.
A Nexus to Nexus 9
Two years ago, patient T6 volunteered for the
BrainGate
clinical trials and had a 100-channel electrode array implanted into
the left side of her brain in regions responsible for movement.
At the time, the Stanford subdivision was working on a prototype
prosthetic device to help paralyzed patients type out words on a
custom-designed keyboard by simply thinking about the words they want to
spell.
The prototype worked like this: the implanted electrodes recorded her
brain activity as she looked to a target letter on the screen, passed
it on to the neuroprosthesis, which then interpreted the signals and
translated them into continuous control of cursor movements and clicks.
In this way, T6 could type out her thoughts using the interface, in a
way similar to an elderly technophobe reluctantly tapping out messages
with a single inflexible finger.
The black-and-white setup was state-of-the-art in terms of response
and accuracy. But the process was painfully slow, and even with
extensive training, T6 often had to move her eyes to the delete button
to correct her errors.
What the field needed was a flexible, customizable and affordable
device that didn’t physically connect to a computer via electrodes,
according to Nuyujukian. We also wanted a user interface that didn’t
look like it was designed in the 80s.
The team’s breakthrough moment came when they realized their
point-and-click cursor system was similar to finger tapping on a
touchscreen, something most of us do every day.

We
were going to design our own touchscreen hardware, but then realized
the best ones were already on the market, laughed Nuyujukian, so we went
on Amazon instead and bought a Nexus 9 tablet.
The team took their existing setup and reworked it so that patient
T6’s brain waves could control where she tapped on the Nexus
touchscreen. It was a surprisingly easy modification: the
neuroprosthetic communicated with the tablet through existing Bluetooth
protocols, and the system was up and running in less than a year.
“Basically the tablet recognized the prosthetic as a wireless
Bluetooth mouse,” explained Nuyujukian. We pointed her to a web browser
app and told her to have fun.
In a series of short movie clips, the team demonstrated patient T6
Googling questions about gardening, taking full advantage of the
autocompletion feature to speed up her research. T6 had no trouble
navigating through tiny links and worked the standard QWERTY keyboard
efficiently.
Think about it, said Nuyujukian, obviously excited. It’s not just a
prettier user interface; she now has access to the entire Android app
store.
According to previous studies, the device can function at least two
years without experiencing any hardware or software issues. The team is
trying to make the implant even sturdier to extend its lifespan in the
brain.
“We set out to utilize what’s already been perfected in terms of the
hardware to make the experience more pleasant,” said Nuyujukian. “We’ve
now showed that we can expand the scope of our system to a standard
tablet.”
But the team isn’t satisfied. They are now working on ways to
implement click-and-drag and multi-touch maneuvers. They also want to
expand to other operating systems, enable the patients to use the device
24/7 without supervision, and expand their pilot program to more
patients in all three of the BrainGate clinical sites.
“Our goal is to unlock the full user interface common to
general-purpose computers and mobile devices,” said Nuyujukian. “This is
a first step towards developing a fully-capable brain-controlled
communication and computer interface for restoring function for people
with paralysis.”