Assistive Technology for Locked-In Syndrome

Bobby Miller

Expanding on the article, “Assistive Technology for Various Levels of Paralysis,” from Nvate’s January issue, this second part examines locked-in syndrome and the assistive technology available.

Locked-in syndrome, allows no movement from any body part—save for the eyes. It might seem impossible to communicate with people who can, almost literally, do nothing but think and look around as others care for them. In fact, back in the days of old, eye movement was the only way we knew these people were conscious, as Roxanne Palmer of the International Business Times explained.

However, thanks to recent innovations, these individuals can now communicate with others.

Eye Technology: Tracking Pupil Movement and Dilation

Since locked-in people can still move their eyes, different technologies can allow them to communicate on a surprisingly high level. For instance, these individuals can use computers. The Tobii PCEye can track a person’s pupil even if they’re wearing lenses or glasses, according to the company’s official website.

The individual looks at the purchased screen, which uses a USB cable to connect to a “normal” computer or laptop equipped with Windows. By moving their pupil to operate the cursor and on-screen keyboard, the person can do just about anything a typical computer user can. Glancing at a taskbar on the right side of the screen allows the user to perform multiple types of clicks.

Nvate Assistive Technology Brainfingers electroencephalography Locked-In Syndrome Paralysis Pupil Movement Tobii PCEye

The user looks at the left screen while the computer’s actual screen sits to the right.
Credit: Tobii’s YouTube page

Researcher Päivi Majaranta of the University of Tampere pointed out that typing with “eye gaze” technology takes two to three times longer than hands-on typing, though. Also, the Tobii PCEye costs $3,900. This might sound expensive, but it grants entirely paralyzed individuals the ability to communicate with others, read material online, write creatively or professionally, and more. You can’t put a price tag on benefits like that.

However, there are people who have total locked-in syndrome. According to the researches behind a study in the Journal of Neurology, a totally locked-in individual does not even have voluntary eye movement. This, of course, makes technology such as the Tobii PCEye completely useless.

Even someone with virtually no control over their bodies has limited forms of communication, though, thanks to a development that just took place in August 2013. According to the International Business Times, scientists at Philipps-University Marburg in Germany have found a “link between pupil dilation and mental effort.” Basically, your pupils will grow bigger if you’re thinking hard about something.

So, to communicate with a totally locked-in person, you can start by asking them a yes-no question such as, “Are you 40 years old?” Tell them to solve the math problem associated with their answer. Display “yes.” Then display a relatively tough math problem. Watch to see if their pupils dilate. After a moment, display “no.” Then display another relatively tough math problem. If their pupils dilate the second time, that means they were thinking hard about the latter math problem, so their answer is “no.” Notice how their answer to the math problem doesn’t matter: we just know they were thinking hard to solve it.

With this in store, we could ask any kind of multiple-choice question to a totally locked-in person. It might take a while and have its limitations, but a family could receive some insight regarding what a loved one is thinking.

Mind-Controlled Computers

The eye is not the only gateway to the soul, however. As aforementioned, brain-machine interfaces have already been applied to robotic limbs. But what if we allowed locked-in people, even those with no eye control, to perform tasks on a computer as well?

Professor Frank Guenther of Boston University decided to try letting locked-in people use computers with their brainwaves. As you’ll recall, brain-machine interfaces worked by letting people imagine moving their limbs, and the robot would mimic the movement. However, Guenther’s technology works by matching a computer cursor to various body commands.

The blog AMS Vans reported that a cap powered by EEG, or electroencephalography, is placed on the patient’s head. If they imagine moving a certain body part, they activate certain brainwaves, which in turn make the cursor move certain directions. For instance, by imagining a right-hand movement, the user puts the cursor on the “ah” vowel sound. Currently, Guenther’s work has been used to allow patients to make basic speech sounds.

Nvate Assistive Technology Brainfingers electroencephalography Locked-In Syndrome Paralysis Pupil Movement Tobii PCEye


Brain Actuated Technologies Inc. has taken things a step further by producing “a headband fitted with sensors [that detect] electrical signals from facial muscles, eye movements, and brainwaves,” according to its website.

Known as Brainfingers, this headband allows individuals with just the slightest ability to control facial muscles to use computers. This won’t help totally locked-in people, unfortunately, but it can benefit a wide variety of individuals. The site explains that “our clients have included individuals with cerebral palsy, Lou Gehrig’s disease, spinal muscular atrophy, muscular dystrophy, traumatic brain injury, and spinal cord injury.”

The website states Brainfingers is easier to use than eye-gaze technology, such as the Tobii PCEye, because it does not require staring at certain points of the screen or involve blinking controls. The site also states that it’s easier to use than head movement technology, such as Camera Mouse.

Unlike other products, Brainfingers can even be used to “enhance [able-bodied people’s] experience of video game play” by allowing them to input commands more quickly than typical hand-eye coordination allows.

Sunil of Seattle, Wash., testified on the website that “the software is very thoughtfully designed and easy to use for the profoundly disabled. It can be fine-tuned in several ways to pick up the faintest signal.”

Nvate Assistive Technology Brainfingers electroencephalography Locked-In Syndrome Paralysis Pupil Movement Tobii PCEye

Alston Daniel, diagnosed with Lou Gehrig’s disease, uses Brainfingers.

Although Sunil can only move his eyes and jaw, he can accomplish many tasks thanks to Brainfingers. “I manage the family finances using Microsoft Money, communicate with family in India using Microsoft Outlook, research anything and everything using Internet Explorer,” he said. This has allowed him to help develop assistive technology and have a “fun life again.”

This revolutionary system comes at a price. “The cost for the basic system is $1,800,” Andrew Junker, the president of Brain Actuated Technologies, said in an email. “The cost for what we call a full-support system, training and support for three years and three year warranty is $3,800.”

If you plan on using it just to enhance your PC gaming experience, though, they can offer it for $1,500. These costs might seem steep, but again, the ability for a paralyzed person to communicate, work, play, and more can definitely make it worth the price.

Additional Resources

Scientists continue to research how paralyzed and other disabled individuals can live much like able-bodied people do. According to the AMS Vans blog, neurology researchers such as Zhigang He of the Harvard Medical Center have found ways to regenerate certain nerve connections in mice after spinal cord injury. If this finding can be applied to humans and their other nerve connections, such as the ones connecting limbs to the brain, researchers may one day cure paralysis.

In the meantime, there are many assistive devices available for those who are paralyzed or suffer from another disorder. Websites such as,, and sort their products by the disability they’re alleviating.

More To Read:

Leave a Reply

Your email address will not be published. Required fields are marked *