Brain Implant Helps 'Locked-In' ALS Woman Communicate
Hanneke de Bruijne has the freedom now to spend more of her time outside.
In 2008, Hanneke de Bruijne was diagnosed with amyotrophic lateral sclerosis, better known as ALS. Gradually the disease afflicted her brain cells and the nerves in her spinal cord until by 2010, she had lost all voluntary control of her muscles. She needed a tracheotomy to breathe. With the hole in her windpipe and the loss of muscle movement, de Bruijne became "locked-in." She couldn't move, she couldn't talk. All she could do was blink.
Like other people in her situation, including renowned theoretical physicist Stephen Hawking, de Bruijne began using a computer system with a camera that tracked her eyes and let her select letters on a screen to spell out words. That was the only way she could express herself.
To people unfamiliar with her, de Bruijne's life might have appeared hopeless. But by the time she met neuroscientist Mariska Vansteensel in 2015, de Bruijne, now age 59, told the researcher, that on a scale from one to 10, she graded the quality of her life as a seven.
"That is really an eye opener for many people, that life can actually be worth living in these kinds of situations," Vansteensel told Seeker.
Other studies have shown that people with locked-in syndrome can be happy and feel good about their lives if they're able to communicate adequately. But eye-tracking systems are not always up to the task. They don't work well outside, where lighting conditions vary, and they frequently need to be recalibrated, if the user moves even slightly.
This week, Vansteensel, an assistant professor at the University Medical Center Utrecht in the Netherlands, and her colleagues report on a brain-controlled interface, or BCI, that could give people with locked-in syndrome a way to communicate in everyday life - inside and outside their homes. Because the system is self-contained and untethered from a computer station, the patient has more freedom.
For de Bruijne this means the ability to spend more time outside.
"She loves nature, she loves going on holidays, she loves to sit in her garden when it's beautiful weather," Vansteensel said. "Now she has our system and she uses it to communicate outside."
The BCI consists of several components starting with a brain implant made of four tiny electrode strips. Two were surgically implanted over a part of the brain that controls hand movement. The other two were placed over a part of the brain activated when a person performs mental calculations, such as counting backward.
Next, the doctors ran a wire beneath the skin to a small transmitter implanted in the chest area. A receiver and an antenna, which can be worn on the outside of the chest, capture the signal from the transmitter and send it wirelessly to a computer tablet that has been coated to reduce glare in the sunlight.
The signals come from de Bruijne when she tries to move her fingers. That's because the part of her brain that controls hand movements activates even if she just thinks about moving her fingers. Those brain signals are picked up by the brain electrodes and sent to the transmitter and ultimately the tablet.
To make a word, the computer screen shows letters being highlighted in succession. Each time a letter is highlighted, de Bruijne does one of two things: if it's the right letter, she tries to move her fingers; if it's the wrong letter, she doesn't. The two "binary" choices simplify the amount of programming needed for the system to interact with her brain. Similar to text messaging, the program is also able to predict the desired word after she chooses one or more letters and when the correct word pops up, de Bruijne can "brain click" to select it.
"The most innovative aspect of this work, from my point of view, is the ability to clearly detect binary signals using relatively simple BCI probes that can be effectively linked to a home-based system for communication," said Nadir Weibel, an assistant research professor of computer science and engineering at UC San Diego. Weibel, who is part of team developing eye-tracking technology to help individuals who are locked-in, was not a part of this research study.
"In addition, this modality seems more flexible than eye-tracking," said Weibel. "Once the system is in place, it does not need to rely on calibrating procedures that are prone to errors due to slight movements of the eye-tracker or the person."
At the time Vansteensel wrote up the research study, de Bruijne had been using the system for nine months with good success. Although it takes about 30 seconds to select a letter, she is satisfied with it because it allows her to enjoy the outdoors. De Bruijne can also use the "brain click" to select a button that generates a sound to alert her caregiver.
Weibel does see some challenges ahead for Vansteensel and her team. Having to undergo a surgical procedure might not appeal to people and that could limit its use. He also thinks that for such a system to be successful, many more tests on many more individuals need to be performed.
"Designing for locked-in individuals is inherently challenging, mainly due to the inability to gather detailed feedback, and too often the interfaces end up being geared to either complex or frustrating interactions for the locked-in user," Weibel said.
So far, de Bruijne is the only person to have used Vansteensel's system, but Vansteensel is aware of the challenge of gathering more data and is in talks with other qualified candidates. She'd like to test the system no only on people with ALS but also on those who may have suffered a brain stem stroke. And she would like to make the system work faster.
"We will definitely be working on that because we think it's really promising," Vansteensel said.
"The interaction with her is a very good life experience," Vansteensel said. "It's really rewarding to have made a difference in even one life."