The Promise of Brain-Computer Interfaces in Rehabilitation

“As computer intelligence gets better, what will be possible when we interface our brains with computers? It might sound scary, but early evidence suggests otherwise: interfacing brains with machines can be helpful in treating traumatic brain injury, repairing spinal cord damage, and countless other applications.”

Bill Maris, Venture Capitalist & Entrepreneur
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Researchers have been investigating the possibilities of brain-computer interfaces or BCIs for quite a while now. At first, these were thought to be tools on one hand to provide constant monitoring of the brain’s electrical activity; this could support a wide range of applications from monitoring epilepsy or ADHD to pain management and sleep assessment. On the other hand, the concept was thought to be a solution for paralyzed people to move and control things around them with only thoughts. Taking it onto the next level, such an implant could also be used as an external hard drive for the mind.

Enhancing cognitive performance would be able to change the lives of millions suffering from memory loss and neurological or psychological disorders. Restorative processes like stroke rehabilitation would also gain from the technology. Or these can help reduce the cognitive effects of aging. No wonder many studies focus on the possibilities such technology can provide for seniors.

I’ve written on the general topic of brain-computer interfaces earlier. But with the rapid development happening in the rehabilitation segment, I thought it might be interesting to revisit the space to review where it stands and explore the potential of the technology to improve people’s lives. I’ll also provide a list of additional resources to explore for those interested in more detail on the topic at the end of this post.

Numerous publications have explored Brain-Computer Interfaces (BCI) systems as rehabilitation tools to help subacute and chronic stroke patients recover upper extremity movement. Recent work has shown that BCI therapy can lead to better outcomes than conventional therapy. BCI, combined with other techniques such as Functional Electrical Stimulation (FES) and Virtual Reality (VR), allows the user to restore the neurological function by inducing the neural plasticity through improved real-time detection of motor imagery (MI) as patients perform therapy tasks.

In recent years, BCIs have successfully enabled dozens of study participants who lost the use of their limbs after strokes, accidents, or diseases such as multiple sclerosis, to control a mouse cursor, keyboard, mobile device, wheelchair, and even a robotic arm that provides sensory feedback to the patient, simply by using their mind. The technology could be a game changer in helping those with paralysis return to work and communicate more quickly and effectively.

One article in Engadget reported that Johns Hopkins University-led researchers had developed a new technique that let a partially paralyzed man feed himself using robotic arms connected through a brain-machine interface. He only had to make small movements with his fists at specific prompts (such as “select cut location”) to have the fork- and knife-equipped arms cut food and bring it to his mouth. He could have dessert within 90 seconds, according to the researchers.

The new method centers on a shared control system that minimizes the mental input required to complete a task. He could map his four-degree freedom of movement (two for each hand) to as many as 12 degrees of freedom for controlling the robot arms. The limbs’ prompt-based intelligent responses also reduced the workload. While still in the early stages of development, this research demonstrates the potential value of the technology.

In another development, BCI manufacturer Blackrock Neurotech and the University of Pittsburgh are working together to make clinical studies more accessible to a greater population of candidates living with paralysis by using a compact, remote BCI system that can be used at home. Researchers will be able to test a broader range of study participants and collect more safety and efficacy data, an essential step to commercializing the technology. The device looks somewhat like an iPad, with a small box the size of a cell phone attached to a type of medical brace. The device can easily attach to a wheelchair and is lightweight. The software used during research trials has also been modified to be operated with little technical support.

Blackrock Neurotech, late last year, was granted Breakthrough Device designation from the Food and Drug Administration for its “MoveAgain” BCI system, which is similar to devices it plans to use in trials and hopes to be its first commercial BCI platform in 2023.

Companies developing brain-computer interfaces for the rehabilitation sector – In the public sector, initiatives such as the Human Brain Project have sought to accelerate research that can help us learn more about our brains to treat diseases better and improve cognitive functioning. In the private sector, several companies are working to develop effective brain-machine interfaces for a wide range of uses. While creating an exhaustive list of companies operating in this space is beyond the scope of a blog post, here are some of the companies focused on rehabilitation BCI tools and platforms:

Neurolutions is a medical device company developing neuro-rehabilitation solutions that utilize a patient’s brain activity to facilitate motor recovery. Neurolutions is spearheading the development of answers that seek to restore function to patients who are disabled as a result of neurological injury. The Neurolutions IpsiHand system provides upper extremity rehabilitation for chronic stroke patients leveraging brain-computer interface and advanced wearable robotics technology.

Image Credit: Neurolutions

BrainQ is pioneering the development of a novel therapy for neuro recovery to reduce disability following stroke and other neuro disorders. The company’s investigative, non-invasive therapeutic wearable device uses frequency-tuned electromagnetic fields to facilitate neuroplasticity processes within the central nervous system. BrainQ’s technology uses explanatory machine learning algorithms to observe natural spectral characteristics found in different motor tasks and derive unique therapeutic insights that are used to target the recovery of impaired neural networks.

Image Credit: BrainQ

A spinout of Oxford University, founded by a global team of experienced entrepreneurs, technologists, and neuroscientists, ni2o is continuing the work started by MIT’s Mind Machine Project – developing a revolutionary brain-computer interface (BCI) that addresses the most pressing and costly medical needs of a rapidly aging global population, the treatment of neurodegenerative brain diseases and disorders.

Cerebtalk – Offers a brain-computer interface (BCI) that provides a communication tool for individuals with severe motor impairments who have limited voluntary movements, e.g., people with amyotrophic lateral sclerosis (ALS), spinal cord injury, stroke, cerebral palsy, and non-verbal autism.

Synchron is developing an implantable device called the Stentrode that aims to provide a safe way for paralyzed patients to achieve direct brain control of mobility-assistive devices. The system involves a small and flexible device that can pass through cerebral blood vessels, allowing it to implant in the brain and interpret electrical data emitted by neurons. The company is currently preparing for early-stage clinical trials to evaluate the safety and feasibility of the device to enable patient-directed brain control.

YouTube Video Credit: Synchron, Inc.

MindMaze – Founded in 2012 as a spin-off from the Swiss Federal Institute of Technology (EPFL), this Swiss startup has taken in $108 million to launch devices that use virtual reality, brain imaging, and gaming technologies to retrain the brain how to work again for those suffering from brain injuries like stroke victims. MindMotionPRO can trick the patient’s brain into believing that immobilized regions of their body are still working, thereby spurring the recovery. The platform uses brain data, movement data, and muscle data to produce interactions in VR with “zero latency.” MindMotionPRO devices have achieved the European equivalent of FDA approval (CE Marked) and are actively used in several top university hospitals across Europe. Mindmaze is now working on getting FDA approval so that the device can be put to use in U.S. hospitals as well.

Image Credit: TechCrunch

BrainGate™ is a transformative neurotechnology owned and operated by Tufts University that uses microelectrodes implanted in the brain to let humans operate external devices such as computers or robotic arms with just their thought. Through years of advanced research, BrainGate™ is at the forefront of enabling severely motor-impaired individuals with the ability to communicate, interact, and function through thought. BrainGate™ is the only technology with an FDA-approved investigational device exemption to conduct human trials of brain-computer interface (BCI) technologies.

Image Credit: BrainGate

The future of BCI in rehabilitation – There are roughly 5.4 million people in the U.S. living with some form of paralysis, making BCIs a distant reality for all but a select few. The BCI field is reaching an inflection point as commercial interests advance research-only technology. Now, with BCI companies hoping to expand the market for the technology, a new wave of users is expected to feel the complex bundle of emotions — fear, uncertainty, joy, excitement, relief, and sadness — experienced by the field’s pioneers. Rehabilitative BCIs have a great potential to help people. The known benefits of the BCIs currently being developed for those with spinal cord injuries, strokes, and other neurological conditions far outweigh the possible issues that may arise.

Additional reading – If you are interested in exploring this topic in more detail, here are some additional resources you might find interesting:

  • The brain-reading devices helping paralyzed people to move, talk and touch – great long-form article by Liam Drew published in Nature on April 20, 2022
  • Will We All Have To Become Biologically Enhanced Superhumans?from Dr. Bertalan Mesko and his team at The Medical Futurist Institute. Broader than just a discussion on BCI in rehabilitation, but worth a read.
  • Plugged In: The Past, Present, and Future of Brain-Computer Interfaces by Audrey Case – Think of this book as “the layperson’s guide to brain-computer interfaces. Audrey discovered that finding material to explain BCIs to those who didn’t work with them intimately was nearly impossible. So she created a resource for non-experts to learn about the technology so they could form their own opinions instead of just believing the hype. She uses her background in bio-engineering to weave the story of how the technology came to be and all the sometimes surprising turns it took to get to where it is today. And, at 99 cents for the Kindle version, this one is a huge bargain.
  • Brain-Computer Interfaces Are Coming. Will We Be Ready?From the Rand Corporation – RAND researchers developed a path for determining where BCI technology stands now and where it could potentially go. They used a comprehensive method that could be applied to other emerging technologies.
  • What Brain-Computer Interfaces Could Mean for the Future of WorkHarvard Business Review article by Alexandre Gonfalonieri – Brain-computer interfaces (BCIs) are slowly moving into the mass market. In the next few years, we might be able to control our PowerPoint presentations or Excel files using only our brains. And companies may want to use BCI technology to monitor the attention levels and mental states of their employees. There are numerous ethical questions and concerns surrounding using BCI technology in the workplace. The technology is well ahead of the policies and regulations that would need to be put in place. But, it’s time for business leaders to start building a BCI strategy as soon as possible to address the potential risks and benefits.

iHuman? – Some Straight Talk on Brain/Computer Interfaces (BCI) in Health Care

“The applications for neural interfaces are as unimaginable today as the smartphone was a few decades ago.”

Chris Toumazou FREng FMedSci, FRS, co-chair, the Royal Society Steering Group on Neural Interface Technologies
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Brain-computer interfaces (or BCIs) are the ultimate examples of convergence. They sit at the intersection of nearly everything discussed on this blog, including biotechnology, nanotechnology, and materials science. There’s also quantum computing, which allows us to model complex environments like the human brain, and artificial intelligence, which helps us interpret what we’ve modeled. And high-bandwidth networks that would enable us to upload neurological signals into the cloud.

A new UK Royal Society report called “iHuman: blurring lines between mind and machine” is for the first time systematically exploring whether it is “right” or not to use neural interfaces – machines implanted in or worn over the body to pick up or stimulate nervous activity in the brain or other parts of the nervous system. It also sets out recommendations to ensure the ethical risks are understood and to set up a transparent, public-driven but flexible regulatory framework that will allow the UK to lead innovative technology in this field.

Many people worldwide already benefit from medical neural interface technologies. In many cases, their conditions have proved drug-resistant, and ‘electroceuticals’ have achieved what pharmaceuticals could not. Cochlear implants that substitute damaged parts of the ear provide hearing for around 400,000 people. Thousands of people with conditions such as Parkinson’s disease, dystonia, and essential tremor have been treated with deep brain stimulation. External, wearable interfaces include a range of devices that assist people who have had a stroke in their rehabilitation. People otherwise unable to communicate have been able to spell out words using brain signals alone, providing them with an invaluable means of interaction.

Other treatments are still being explored in the laboratory, such as transcranial direct current stimulation (tDCS) for depression. Others are in the early stages of medical use, such as DBS used for epilepsy or the ‘Mollii Suit’ body garment that delivers electrical stimulation to people with muscle spasticity caused by conditions like stroke or cerebral palsy. By 2040, according to the Royal Society report, conditions like Alzheimer’s disease will probably be treated using a BCI.

“In 10 years’ time this is probably going to touch millions of people.”

Tim Constandinou, Co-Chair, Royal Society Steering Group on Neural Interface Technologies

What’s the best way to segment the brain-computer interface space? – As with all emerging technologies, there are multiple ways to segment the neural interface market. The method that I’ve found works best for me in discussing this topic is to segment by whether the technology is invasive (sub-segmented into recording and stimulating categories) or non-invasive (also sub-segmented into recording and stimulating categories). In the two sections that follow, I’ll list some of the technologies in each category. (For a detailed description of each technology, see the entire Royal Society report pages 30-33, using the link above.)

Invasive technologies

Non-invasive technologies

Recording category

Recording category

  • ECoG – electrocorticography
  • Cortical implant
  • Neural dust
  • Neural lace
  • Neuropixels
  • Stentrodes
  • Optogenetics
  • EEG – Electroencephalography
  • MEG – Magnetoencephalography
  • fMRI – Functional magnetic resonance imaging
  • fNIRS – Functional near-infrared spectroscopy
  • MMG – Mechanomyography

Stimulation category

Stimulation category

  • Cochlear implants
  • DBS – Deep brain stimulation
  • VNS – Vagus nerve stimulation
  • Retinal implants
  • Vestibular implants
  • FES – Functional electrical stimulation
  • tDCS – Transcranial direct current stimulation
  • TENS – Transcutaneous electrical nerve stimulation
  • TMS – Transcranial magnetic stimulation

Where we are today – Scientists in this pioneering field make it clear that we have not even scratched the surface of the potential applications of brain-computer interfaces, which could not only help solve medical issues like dementia, epilepsy, untreatable depression, and obesity but could help people communicate without sound and even without words. We could share sensory experiences with others far away, as by sending “neural postcards,” letting others visually experience their trip or “taste” the food they are eating, by sharing the brain’s neural activity.

In its 2018 report, The Market for Neurotechnology: 2018 – 2022 (recently updated to 2020-2024 – purchase required), Neurotech reports projected that the overall worldwide market for neurotechnology products – defined as “the application of electronics and engineering to the human nervous system” – would be $8.4 billion in 2018, rising to $13.3 billion in 2022. The 2018 figure represents less than 1% of the estimated total 2018 global spending on research and development of around $2 trillion or less than 5% of all estimated life science research and development spending.

Probably the most publicized effort in the BCI space has been Neuralink, Elon Musk’s initiative that will allow paralyzed people to use computers to communicate using their thoughts alone. This could improve the quality of life for people with locked-in syndrome, for instance, where the brain is normal but is cut off from the rest of the body. However, Musk has plans that are far in advance of helping people to replace something they have lost. He foresees that artificial intelligence (AI) could advance so rapidly and so much that it forces humans to become subsidiary, something like a house pet. Installing an AI layer would be an excellent way to stay in step with AI instead, he says, and the “neural lace” interface his company is producing is an initiative designed to do just that. He plans to begin clinical trials of these neural threads next year. Here’s a brief video showing how Neuralink works:

Neuralink plans a two-gigabit-per-second wireless connection from the brain to the cloud and wants to begin human trials by the end of 2021.

The other startup receiving a ton of press coverage is Kernel, funded by Bryan Johnson, who sold his payments company to Pay Pal for $800 million in 2013. Johnson then started a venture fund called the OS Fund, which aims to “rewrite the operating systems of life” for the benefit of humanity. Johnson has courted some big names in the neuroscience field from the MIT community. Ed Boyden, a professor of biological engineering and brain and cognitive sciences at MIT, has signed on as a chief scientific advisor. And Adam Marblestone, a neuroscientist who focuses on improving data collection from the brain, is now Kernel’s chief strategy officer, having worked in the past with Boyden’s Synthetic Neurobiology Group.

“Brain science is the new rocket science.”

Bryan Johnson, Kernel founder

In addition to these two big-budget, high-profile companies, other researchers and companies are exploring the development of neural interfaces. BrainGate is a long-running multi-institution research effort in the US to develop and test novel neurotechnology to restore communication, mobility, and independence in people whose minds are okay but who have lost bodily connection due to paralysis, limb loss, or neurodegenerative disease. Paradromics is focused on many more and smaller electrodes but aims for an even higher density of probes over the face of its neural implant. Synchron, based in Australia and Silicon Valley, has a different approach. The device avoids open brain surgery and scarring because it is inserted using a stent through a vein in the back of the neck. Once in position next to the motor cortex, the stent splays out to embed 16 metal electrodes into the blood vessel’s walls from which neuronal activity can be recorded.

And recently, a newly formed MIT research center was announced that is explicitly studying the fusion of the human body with advanced technology like robotic exoskeletons and brain-computer interfaces — with the ambitious goal of developing systems to restore function for people with physical and neurological disabilities. The new research center will fall under the leadership of MIT Media Lab professor Hugh Herr, who is a double amputee himself and has come to be known as a leader in the field of robotic prosthetics. In the MIT announcement, Herr said he sees this new initiative as an essential step toward eliminating physical disabilities altogether.

“We must continually strive towards a technological future in which disability is no longer a common life experience.”

Hugh Herr, MIT Media Lab

The MIT faculty working within the new research center will have three primary goals, according to the announcement. The first is to develop what MIT is calling a “digital nervous system,” or tools that circumvent spinal cord injuries by stimulating muscles that have been cut off from the central nervous system — which is remarkably similar to an unrelated neural implant currently being tested in human volunteers. On top of that, the center aims to improve exoskeleton technology to help people with weakened muscles move around naturally, as well as to develop new bionic limbs that can restore a complete, natural sense of touch.

What are the ethical issues raised by the development of brain-computer interfaces? – Some of the most prominent are: how, if at all, should use of the technologies be limited; what ‘normality’ means; how can privacy be protected and which specific concerns, for example around surveillance, might be felt strongly by particular social groups; whether neural interfaces may contribute to widening inequalities; and what it means to be human.

“As our experience with social media has shown, we do need to think ahead to guard against possible harmful uses. If recent experience has shown us anything, it’s that individual consent and opting in or out is not enough to protect either individuals or society more widely.”

Sarah Chan, Co-author, iHuman: blurring lines between mind and machine

My take – Brain-computer interfaces hold enormous promise as life-changing technologies for people with a variety of conditions. However, the technique is still in its infancy, and designing sensors that can effectively and safely monitor brain activity is a work in progress. Part of the issue is the complexity of the brain, and capturing this using a single sensor or affixing enough sensors in place which is extremely difficult. The future impact of BCI in terms of patient care is slowly starting to come into focus. As with most emerging technologies, regulatory, privacy, and reimbursement issues lag the development of the technology itself. For these and other reasons, the clinical use of these BCI technologies will be limited to Universities and health systems with comprehensive neuro service line programs for the foreseeable future.