Restoring Ability: Project NEUWalk

neuwalkIn the past few years, medical science has produced some pretty impressive breakthroughs for those suffering from partial paralysis, but comparatively little for those who are fully paralyzed. However, in recent years, nerve-stimulation that bypasses damaged or severed nerves has been proposed as a potential solution. This is the concept behind the NEUWalk, a project pioneered by the École Polytechnique Fédérale de Lausanne (EPFL) in Switzerland.

Here, researchers have figured out a way to reactivate the severed spinal cords of fully paralyzed rats, allowing them to walk again via remote control. And, the researchers say, their system is just about ready for human trials. The project operates on the notion that the human body requires electricity to function. The brain moves the body by sending electrical signals down the spinal cord and into the nervous system.

spinal-cord 2When the spinal cord is severed, the signals can no longer reach that part of the spine, paralysing that part of the body. The higher the cut, the greater the paralysis. But an electrical signal sent directly through the spinal cord below a cut via electrodes can take the place of the brain signal, as the team at EPFL, led by neuroscientist Grégoire Courtine, has discovered.

Previous studies have had some success in using epidural electrical stimulation (EES) to improve motor control where spinal cord injuries are concerned. However, electrically stimulating neurons to allow for natural walking is no easy task, and it requires extremely quick and precise stimulation. And until recently, the process of controlling the pulse width, amplitude and frequency in EES treatment was done manually.

brainwavesThis simply isn’t practical, and for two reasons: For starters, it is very difficult for a person to manually adjust the level of electrostimulation they require to move their legs as they are trying to walk. Second, the brain does not send electrical signals in an indiscriminate stream to the nerves. Rather, the frequency of the electrical stimulation varies based on the desired movement and neurological command.

To get around this, the team carefully studied all aspects of how electrical stimulation affects a rat’s leg movements – such as its gait – and was therefore able to figure out how to stimulate the rat’s spine for a smooth, even movement, and even take into account obstacles such as stairs. To do this, the researchers put paralyzed rats onto a treadmill and supported them with a robotic harness.

NEUWalk_ratsAfter several weeks of testing, the researchers had mapped out how to stimulate the rats’ nervous systems precisely enough to get them to put one paw in front of the other. They then developed a robust algorithm that could monitor a host of factors like muscle action and ground reaction force in real-time. By feeding this information into the algorithm, EES impulses could be precisely controlled, extremely quickly.

The next step involved severing the spinal cords of several rats in the middle-back, completely paralyzing the rats’ lower limbs, and implanted flexible electrodes into the spinal cord at the point where the spine was severed to allow them to send electrical signals down to the severed portion of the spine. Combined with the precise stimulation governed by their algorithm, the researcher team created a closed-loop system that can make paralyzed subjects mobile.

walkingrat.gifAs Grégoire Courtine said of the experiment:

We have complete control of the rat’s hind legs. The rat has no voluntary control of its limbs, but the severed spinal cord can be reactivated and stimulated to perform natural walking. We can control in real-time how the rat moves forward and how high it lifts its legs.

Clinical trials on humans may start as early as June 2015. The team plans to start testing on patients with incomplete spinal cord injuries using a research laboratory called the Gait Platform, housed in the EPFL. It consists of a custom treadmill and overground support system, as well as 14 infrared cameras that read reflective markers on the patient’s body and two video cameras for recording the patient’s movement.

WorldCup_610x343Silvestro Micera, a neuroengineer and co-author of the study, expressed hope that this study will help lead the way towards a day when paralysis is no longer permanent. As he put it:

Simple scientific discoveries about how the nervous system works can be exploited to develop more effective neuroprosthetic technologies. We believe that this technology could one day significantly improve the quality of life of people confronted with neurological disorders.

Without a doubt, restoring ambulatory ability to people who have lost limbs or suffered from spinal cord injuries is one of the many amazing possibilities being offered by cutting-edge medical research. Combined with bionic prosthetics, gene therapies, stem cell research and life-extension therapies, we could be looking at an age where no injury is permanent, and life expectancy is far greater.

And in the meantime, be sure to watch this video from the EPFL showing the NEUWalk technology in action:


The Future is Here: DARPA’s Nervous System Implants

DARPA_implantHard on the heels of their proposed BRAIN initiative – a collaborative research initiative to map the activity of every neuron in the human brain – DARPA has announced a bold new program to develop tiny electronic implants that will be able to interface directly with the human nervous system to control and regulate many different diseases and chronic conditions, such as arthritis, PTSD, Crohn’s disease, and depression.

The program, called ElectRx (pronounced ‘electrics’), ultimately aims to replace medication with “closed-loop” neural implants which monitor the state of your health and then provide the necessary nerve stimulation to keep your organs and biological systems functioning properly. The work is primarily being carried out with US soldiers and veterans in mind, but the technology will certainly percolate down to civilians as well.

electrx-darpaThe ElectRx program will focus the relatively new area of medical therapies called neuromodulation, which seeks to modulate the nervous system to improve neurological problem. Notable examples of this are cochlear implants which restore hearing by modulating your brain’s auditory nerve system, and deep brain stimulation (DBS) which is apparently capable of curing/regulating conditions  like depression and Parkinson’s by overriding erroneous neural spikes.

So far, these implants have been fairly large, which makes implantation fairly invasive and risky. Most state-of-the-art implants also lack precision, with most placing the stimulating electrodes in roughly the right area, but which are unable to target a specific bundles of nerves. With ElectRx, DARPA wants to miniaturize these neuromodulation implants so that they’re the same size as a nerve fiber.

electrx-darpa-implant-diagramThis way they can be implanted with a minimally invasive procedure (through a needle) and attached to specific nerve fibers, for very precise stimulation. While these implants can’t regulate every condition or replace every medication (yet), they could be very effective at mitigating a large number of conditions. A large number of conditions are caused by the nervous system misfiring, like inflammatory diseases, brain and mental health disorders.

Currently, a variety of drugs are used to try and cajole these awry neurons and nerves back in-line by manipulating various neurotransmitters. However, the science behind these drugs is not yet exact, relying heavily on a trial-and-error approach and often involving serious side-effects. Comparatively, an electronic implant that could “catch” the misfire, cleans up the signal, and then retransmits it would be much more effective.

cochlear_implantAs DARPA’s Doug Weber explained:

The technology DARPA plans to develop through the ElectRx program could fundamentally change the manner in which doctors diagnose, monitor and treat injury and illness. Instead of relying only on medication — we envision a closed-loop system that would work in concept like a tiny, intelligent pacemaker. It would continually assess conditions and provide stimulus patterns tailored to help maintain healthy organ function, helping patients get healthy and stay healthy using their body’s own systems.

Despite requiring a lot of novel technological breakthroughs, DARPA is planning to perform human trials of ElectRx in about five years. The initial goal will be improving the quality of life for US soldiers and veterans. And while they have yet to announce which conditions they will be focusing on, it is expected that something basic like arthritis will be the candidate – though there are expectations that PTSD will become a source sooner other than later.

AI'sAnd this is just the latest neurological technology being developed by DARPA. Earlier in the year, the agency announced a similar program to develop a brain implant that can restore lost memories and experiences. A joint fact sheet released by the Department of Defense and the Veteran’s Association revealed that DARPA also secured 78 million dollars to build the chips as part of the government’s Brain Research through Advancing Innovative Neurotechnologies (BRAIN) program.

While DARPA’s ElectRx announcement is purely focused on the medical applications of miniature neural implants, there are of course a variety of other uses that might arise from elective implantation – for soldiers as well as civilians. With a few well-placed implants in a person’s spine, they could flip a switch and ignore any pain reported by your limbs, allowing them to withstand greater physical stress or ignore injuries.

posthumanImplants placed in muscle fibers could also provide added electrostimulation to provide extra boosts of raw muscle power. And With precision-placed implants around the right nerve fibers, people could gain manual control of their organs, allowing them to speed up or slow down their hearts, turbo-charge their livers, or tweak just about any other function of their bodies.

The age of the Transhuman looms, people!