It wasn’t too long ago that people thought we’d have flying cars and robot servants by now. This may not be the case, but robotics and brain-computer interfaces are advancing rapidly to the point where brain-controlled neuroprosthetics with sensory feedback is a reality – even if mostly in a lab setting.
Neuroprosthetics are devices controlled by a neural link between sensors that read brain waves and devices controlled by those impulses. Newer brain-computer interfaces allow two-way communication, allowing a robotic limb with sensors to send tactile signals back to the brain.
This research provides promising avenues for amputees to get a replacement limb that feels close to having a biological one. These technologies are even restoring mobility to people with paralysis.
In 2019 we are seeing the very first instances of neuroprosthetic devices that are designed to work outside of a lab. Read on to learn about the latest projects in neuroprosthetics it is worth keeping an eye on.
Brain Mind Institute of the Life Science School at the École Polytechnique Fédérale de Lausanne (EPFL)
EPFL, known as the Swiss Federal Institute of Technology Lausanne in English, is at the forefront of neuroprosthetic research. Their Brain Mind Institute (BMI), headed up by Professor Gregoire Courtine, is associated with many of the neuroprosthetic research projects that make headlines. Their projects have major implications for amputees and those who suffer from paralysis.
Neuroprosthetics and Paralysis
In 2014, EPFL announced the ability to control the hind legs of paralyzed rats that had severed spinal cords. The implanted electrodes in the lower spinal cord that sent electrical impulses through the severed spine and the rats’ nervous systems. After some trial and error, they were able to get the rats to adopt a normal gait and even overcome obstacles. In this instance, the electrical impulses were controlled by the scientists themselves.
Fast-forward to 2016 to a joint-project between EPFL, Brown University, Medtronic and Fraunhofer ICT-IMM in Germany. They were able to give rhesus macaques with a paralyzed leg the ability to walk normally using impulses from their own brains. They first mapped the brain patterns associated with the walking of healthy macaques. Then they implanted a wireless neurosensor in the injured primates’ brains and electrodes in their lumbar spine. The brain chip was able to read the signals associated with walking, send them to a computer, which then stimulated the electrodes in the spine to allow them to walk.
Today, human subjects are beginning to benefit from this same technology:
All of these discoveries have helped dramatically advance prosthetic technology as well.
Neuroprosthetics and Amputation
EPFL’s neuroprosthetic research for amputees from the past several years is particularly promising. They have created arm and hand prosthetics for amputees that provide the sensation of touch by sending signals through electrodes implanted in nerves of the residual limb. Upper-limb amputees can determine how hard or soft an object is, its shape, position, size, how much pressure they are applying to it, and even the texture of a surface. By using these prosthetics in combination with visual VR therapy, the amputee can overcome the disassociation that occurs with most prosthetics by extending their perception of a phantom limb into the device.
The team has recently announced the potential to drastically decrease the amount of training time required with brain-machine interfaces. Previously it would take many hours or days to properly map a user’s brain and train them to control a neuroprosthetic. With this latest research, effective training time for many subjects is now down to 30 minutes.
Other Neuroprosthetic Technology Projects to Watch
DeTOP aka “Dexterous Transradial Osseointegrated Prosthesis with neural control and sensory feedback”
DeTOP is a research project funded by the European Commission to develop tactile and dexterous prosthetics for transradial amputees. They very recently pioneered the first prosthetic for below-elbow amputees that is usable for daily life outside of a lab setting.
“The breakthrough of our technology consists on enabling patients to use implanted neuromuscular interfaces to control their prosthesis while perceiving sensations where it matters for them, in their daily life,” says Dr. Ortiz Catalan, Assoc. Prof. at Chalmers University of the Technology and head of the Biomechatronics and Neurorehabilitation Lab.
SensArs is a company whose mission is to re-enable people with limb loss and nerve-damaged persons by:
- Restoring their complete sensory-motor functionality
- Diminishing phantom limb pain
- Enabling them to feel the artificial limb as part of their own body
They are working on a solution called SENSY, a neuroprosthetic device that is implanted in residual nerves. Their aim is to create a commercially viable solution that would restore meaningful tactile sensation to the user.
BrainGate2 Clinical Trial
This early-stage research project led by Dr. Bolu Ajiboye of Case Western Reserve University in Cleveland has allowed a quadriplegic to control his limbs using his thoughts. Sensors were surgically implanted in the subject’s brain, and electrodes implanted in his arm and hand. He trained with scientists over 4 months using VR to properly send the signals to the electrodes and control his arm and hand. The subject was able to both eat and drink on his own, albeit slowly, during the two-year trial.
Want More Information on Upcoming Prosthetic Technology?
Neuroprosthetic research is gaining traction quickly, and each advance builds upon the next. It won’t be long before we begin to see more prosthetics available commercially that get close to restoring the function of a biological limb.
For more information on how neuroprosthetic technology works, be sure to read our previous post: Neuroprosthetic Limbs: Exploring the Future of Prosthetics.
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Photo Credit: EPFL