BCI lets a man completely “locked up” communicate with his son, ask for a beer

The Wyss Center for Bio and Neuroengineering has developed a communication platform for people with complete confinement syndrome.

A 36-year-old German man in a completely locked-up state has been fitted with a new brain-computer interface (BCI) system that relies on auditory feedback. Man has learned to modify his brain activity in response to this auditory feedback to compose simple messages. He used this ability to ask for a beer, to have his guardians play his favorite rock band and to communicate with his young son, according to a recent article published in Nature Communication.

BCI interact with brain cells, recording the electrical activity of neurons and translating these signals into action. Such systems typically involve electrode sensors to record neural activity, a chipset to transmit the signals, and computer algorithms to translate the signals. BCIs can be external, similar to medical EEGs in that the electrodes are placed on the scalp or forehead with a wearable cap, or they can be implanted directly into the brain. The first method is less invasive but can be less accurate because more noise interferes with the signals; the latter requires brain surgery, which can be risky. But for many paralyzed or confined patients, it’s an acceptable risk.

Last year, we witnessed two milestones on the BCI front. In March 2021, we reported on Neuralink’s demonstration of a monkey playing pong using a brain implant wirelessly connected to the game computer. To achieve this, the company managed to miniaturize the device and make it communicate wirelessly. In April 2021BrainGate Consortium researchers successfully demonstrated high-throughput wireless BCI in two tetraplegic human subjects.

This latter study used a wired implanted BCI. People with amyotrophic lateral sclerosis (ALS), colloquially known as Lou Gehrig’s disease, often become paralyzed and unable to communicate, despite being cognitively functional. Several assistive devices have been developed to help restore communication ability, including BCIs that rely on eye movement. But patients in a fully enclosed state lost even that tiny bit of motor control. This study documents the first successful demonstration of BCI-assisted communication in a completely confined patient.

The German man in the study was diagnosed with progressive muscular atrophy in August 2015, a variant of ALS that selectively affects motor neurons. Within months he was unable to walk or communicate verbally, and in July 2016 he was being artificially ventilated and fed through a tube. The man initially communicated via an assistive device based on eye movements, but his condition deteriorated.

Enlarge / The single case study involved a 36-year-old German man who had lost the ability to voluntarily control his eye movements.

Wyss Center for Bio and Neuroengineering

Realizing it was only a matter of time before he completely lost control of his eye movements, the man’s family interviewed co-authors Niels Birbaumer from the University of Tübingen and Ujwal Chaudhary from ALS Voice gGmbH in Germany on alternative options. At first, the man started using an external BCI system that allowed limited “yes” or “no” answers, which the man could use to select letters to form words and sentences. But Birbaumer and Chaudhary knew that even that would soon not be enough when the man was completely locked up.

An implanted BCI was deemed the best option, and neurosurgeons in Munich performed the operation in March 2019. They placed two arrays of microelectrodes in the patient’s left motor cortex (the dominant side) to detect neural signals, which could be sent via a wired connection to a computer for processing. The NeuroKey software then decodes this data and outputs it as auditory feedback tones. The patient quickly learned to modulate the sound pitch and eventually modulate his neural firing rate to match the frequency of the feedback. After several months of training sessions, the man could select letters and spell words to communicate.

The first message was a simple thank you to Birbaumer and the rest of the team. Other messages related to the man’s care preferences: asking for a head massage or more gel on his eye (which was prone to dryness) and asking for a higher head position when visitors were present. He even made suggestions to improve the performance of the spelling system.

The man learned to alter his own brain activity in response to audio feedback and could select letters to form words and sentences.
Enlarge / The man learned to alter his own brain activity in response to audio feedback and could select letters to form words and sentences.

Wyss Center for Bio and Neuroengineering

Eventually, he might make specific dietary requests for his feeding tube: meat soup, sweet pea soup, and potato curry. And he asked for a beer and for his guards to play his favorite band, Tool, real loud. But it’s the communications with her young son that touch the heart, despite the article’s detached academic tone:

ich liebe meinen coolen (son’s name) – “I love my cool son” on day 251; ‘(son’s name) willst du mit mir bald disneys robin hood anschauen‘- ‘Would you like to watch Disney’s Robin Hood with me’ at day 253; ‘alles von den dino ryders und brax autobahnund alle aufziehautos‘ – ‘all dino riders and brax and cars’ on day 309; ‘(son’s name) moechtest du mit mir disneys die hex und der zauberer anschauen auf amazon‘ – ‘would you like to watch disney’s witch and wizard with me on amazon’ on day 461; ‘mein groesster wunsch ist eine neue bett und das ich morgen mitkommen darf zum grillen‘ – ‘My greatest wish is a new bed and that tomorrow I come with you for the barbecue’ at day 462.

The authors acknowledge that the communication rates of their system were much lower than those measured in other studies involving ALS patients who were not fully enclosed, and they will continue to refine and improve their system. I doubt too much of this German and the spirit of his family since Birbaumer, Chaudhary and their co-authors offered them the priceless gift of reconnection.

DOI: Nature Communications, 2022. 10.1038/s41467-022-28859-8 (About DOIs).

Listing Image By Wyss Center for Bio and Neuroengineering

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