Brain-Computer Interface Lets Unresponsive ICU Patients Control Sound
A Columbia study in Brain shows a noninvasive EEG brain-computer interface let one in three unresponsive ICU patients control a tone using thought alone.
Narration isn’t available yet.
A noninvasive brain-computer interface allowed some brain-injured ICU patients who appeared completely unresponsive to control a sound using only their thoughts, according to a Columbia University study published October 22 in the journal Brain. About one in three of the 41 patients tested learned to raise or lower the pitch of a beeping tone within days of a severe brain injury. The researchers say the work could eventually give patients with hidden consciousness a way to communicate.
What did the Columbia study find?
The team, led by neurologist Jan Claassen of Columbia University Vagelos College of Physicians and Surgeons and NewYork-Presbyterian/Columbia University Irving Medical Center, tested the system on 41 clinically unresponsive patients with acute brain injury a few days after they were admitted to the hospital.
After a short training period, roughly a third of the patients were able to control the tone by thought alone. Every patient who had been identified as having cognitive motor dissociation, a form of hidden consciousness, through a separate exam was among those who succeeded. Some reached that point within a few days of their injury.
The paper, titled “Clinically unresponsive patients with acute brain injury activate a brain-computer interface,” lists Qi Shen as first author alongside a team of Columbia and NewYork-Presbyterian clinicians and researchers.
How does the brain-computer interface work?
Unlike implanted devices from companies working on brain chips, this system relies on standard EEG electrodes placed on the scalp, the same kind already used for routine brain monitoring in intensive care units.
The setup works in a few steps:
- Patients hear a beeping tone through headphones.
- A recorded voice asks them to change the tone’s frequency by imagining opening and closing their hands.
- A bedside computer analyzes the EEG signals in real time and adjusts the tone accordingly.
- The recorded voice offers encouragement and congratulates patients when they hit a target.
Because the hardware is already standard in ICUs, the researchers argue the approach could be far easier to deploy than alternatives. Functional MRI has previously been used to get yes-or-no answers from a single unresponsive patient, but it is not practical for routine bedside use.
What is cognitive motor dissociation?
Cognitive motor dissociation, or CMD, describes patients who appear to try to follow commands but cannot move their muscles to show it. Claassen’s team has linked the condition to a breakdown in communication between higher-order thinking regions of the brain and the motor regions that control movement.
In 2019, the same group used standard EEG and artificial intelligence to detect signs of hidden consciousness in 15% of unresponsive brain-injured patients, a finding that surprised the critical care field. Their research has also shown that patients with CMD are more likely to regain consciousness and recover significant day-to-day function. However, tools to identify CMD are still confined to research settings.
Why it matters
For families and clinicians, knowing whether a seemingly unresponsive patient is aware can shape decisions about care. A bedside tool that both detects awareness and offers a channel for basic responses could change how these patients are treated in the first critical days after injury.
Claassen is careful not to overstate the result. “Our brain-computer interface is only a first step,” he said in Columbia’s announcement, while adding that the work suggests such patients might one day be given a voice. He noted that EEG is already part of everyday ICU practice, which could help the technology spread if it matures.
Limitations and what happens next
The study shows control of a single tone, not open communication. Only about a third of patients could use the system, it required training, and public summaries do not specify how many of the 41 patients had CMD.
The researchers now plan to refine the interface so patients could signal needs such as pain or hunger. Participants and family members who tried the system called it helpful and suggested personal touches, including using a loved one’s voice, adding culturally relevant details, and building in ways to detect pain, hunger and awareness.
The work was funded by the National Institutes of Health, Paris Brain Institute America, the Canadian Institutes of Health Research, the Fondation du Centre hospitalier de l’Université de Montréal and the Royal College of Physicians and Surgeons of Canada.