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:


Sources:
cnet.com, motherboard.com
, actu.epfl.ch

The Future is Here: The Telescopic Contact Lense

telescopic_contact_lensWhen it comes to enhancement technology, DARPA has its hands in many programs designed to augment a soldier’s senses. Their latest invention, the telescopic contact lens, is just one of many, but it may be the most impressive to date. Not only is it capable of giving soldiers the ability to spot and focus in on faraway objects, it may also have numerous civilian applications as well.

The lens is the result of collaboration between researchers from the University of California San Diego, Ecole Polytechnique Federale de Lausanne in Switzerland, and the Pacific Science & Engineering Group, with the financial assistance of DARPA. Led by Joseph Ford of UCSD and Eric Tremblay of EPFL, the development of the lens was announced in a recent article entitled “Switchable telescopic contact lens” that appeared in the Optics Express journal.

telescopic-contact-lens-2

In addition to being just over a millimeter thick, the lens works by using a series of tiny mirrors to magnify light, and can be switched between normal and telescopic vision, which is due to the lens having two distinct regions. The first The center of the lens allows light to pass straight through, providing normal vision. The outside edge, however, acts as a telescope capable of magnifying your sight by close to a factor of three.

Above all, the main breakthrough here is that this telescopic contact lens is just 1.17mm thick, allowing it to be comfortably worn. Other attempts at granting telescopic vision have included a 4.4mm-thick contact lens (too thick for real-world use), telescopic spectacles (cumbersome and ugly), and most recently a telescopic lens implanted into the eye itself. The latter is currently the best option currently available, but it requires surgery and the image quality isn’t excellent.

Telescopic-Contact-Lens-3To accomplish this feet of micro-engineering, the researchers had to be rather creative. The light that will be magnified enters the edge of the contact lens, is bounced around four times inside the lens using patterned aluminum mirrors, and then beamed to the edge of the retina at the back of your eyeball. Or as the research team put it in their article:

The magnified optical path incorporates a telescopic arrangement of positive and negative annular concentric reflectors to achieve 2.8x magnification on the eye, while light passing through a central clear aperture provides unmagnified vision.

To switch between normal and telescopic vision, the central, unmagnified region of the contact lens has a polarizing filter in front of it — which works in tandem with a pair of 3D TV spectacles. By switching the polarizing state of the spectacles – a pair of active, liquid crystal Samsung 3D specs in this case – the user can choose between normal and magnified vision.

AR_glassesThough the project is being funded by DARPA for military use, the research team also indicated that the real long-term benefits of a device like this one come in the form of civilian and commercial applications. For those people suffering from age-related macular degeneration (AMD) – a leading cause of blindness for older adults – this lens could be used to correct for vision loss.

As always, enhancement technology is a two-edged sword. Devices and systems that are created to address disabilities and limitations have the added benefit of augmenting people who are otherwise healthy and ambulatory. The reverse is also true, with specialized machines that can make a person stronger, faster, and more aware providing amputees and physically challenged people the ability to overcome these imposed limitations.

telescopic-contact-lens-5However, before anyone starts thinking that all they need to slip on a pair of these to get superhero-like vision, there are certain limitations. As already stated, the lens doesn’t work on its own but needs to be paired with a modified set of 3D television glasses for it to work. Simply placing it on the pupil and expecting magnified vision is yet not an option.

Also, though the device has been tested using computer modeling and by attaching a prototype lens to a optomechanical model eye, it has not been tested on a set of human eyes just yet. As always, there is still a lot of work to do with refining the technology and improving the image quality, but it’s clear at this early juncture that the work holds a lot of promise.

It’s the age of bionic enhancements people, are we find ourselves at the forefront of it. As time goes on, we can expect such devices to become a regular feature of our society.

Sources: news.cnet.com, extremetech.com