Motorized, computer-controlled braces and frames are making the concept of the bionic human into reality. Experts discuss how these exoskeletons work and how they may be used in the future.
- Dr. Alberto Esquenazi, Chief Medical Officer, Moss Rehab
- Dr. Peter Gorman, Chief, Division of Rehabilitation Medicine, University of Maryland Rehabilitation and Orthopedic Institute and attending physician, Baltimore VA Medical Center
- Dr. Homayoon Kazerooni, Professor of Mechanical Engineering, University of California Berkeley, Director, Berkeley Robotics and Human Engineering Laboratory and founder and Chief Scientist, Berkeley Bionics
17-04 Exoskeletons: Enabling paraplegics to walk again
Reed Pence: The concept of the bionic human; the idea that technology can augment our bodies, giving us superhuman strength and abilities have fascinated us for a long time. TV shows like the 6 million dollar man and Bionic Woman were popular back in the 1970’s and todays Iron Man franchise is still a huge hit. Obviously we haven’t reached those levels of advanced technology, but there are men and women today using bionic technology to make them stronger and more mobile with a device called an “Exoskeleton.”
Dr. Alberto Esquenazi: It’s actually pretty amazing sensation – you are wearing this, they’re called exoskeletons, because they’re just essentially a skeleton surrounding you or armour if you want to think about in in simplistic ways. But it is motorized and so you can control when to go from sit to stand, when to go from stand to walk, when to go from walking to stopping and then when to sit down again.
Pence: That’s Dr. Alberto Esquenazi, Chief Medical Officer at Moss Rehab in Philadelphia. He uses exoskeletons at his center but not to fight the bad guys.
Esquenazi: Exoskeletons are devices that allow an individual that is paralyzed to be mobile again. So this device is characterized by having motors and so there is a power generation in the device and then there are batteries. And usually they will be controlled by a computer. At this point they’re intended for people who have their own legs and you’re supplementing their weak or paralyzed limbs.
Pence: Currently four manufacturers produce exoskeletons in the United States and depending on the model, the devices can weigh anywhere between 20 and 50 pounds. But if designed properly, the user doesn’t feel the weight or become fatigued or drenched with sweat. Rather, the exoskeleton walks the person, who may have not walked in years.
Dr. Peter Gorman: These individuals’ speeds of walking approach normal walking speeds but we’re not there yet.
Pence: That’s Dr. Peter Gorman, Chief of the Division of Rehabilitation Medicine at the University of Maryland Rehabilitation and Orthopedic Institute and attending physician at the Baltimore VA Medical Center.
Gorman: We estimate that it takes about the speed of .4 meters per second; 1.5 fee per second, to get across the street safely. We really were looking at most folks walking with these devices at about half that rate right now. But some of them are athletic and adventurous individual who have started to achieve those rates and that’s really exciting for them.
Pence: According to the National Spinal Cord Injury Statistical Center, about 275,000 people in the United States live with spinal cord injuries. And about 12, 500 new cases occur every year. Most spinal cord injuries are caused by car accidents followed by accidental falls and gunshot wounds.
Gorman: Every individual that I’ve come across with spinal cord injury entertains the idea of wanting to return to upright walking if they could. But realistically, using the older technologies such as long-leg bracing or electrical stimulation technologies that’ve been around for a few decades or the newer exoskeletal robotics – those take effort and training and is not as energy efficient as is a wheelchair. But it still is a major step forward in these patients who can stand and can look at other individuals in their lives eye-to-eye instead of always from the seated position. Can do things that are critical to their lives that require standing posture – it makes a big difference.
Pence: However, training with an exoskeleton can be grueling. Up to 3 one hour sessions a week for 3 months – and that’s just to eventually walk across a room upright. Still using crutches for balance. Esquenazi says, patients have to be extremely motivated to train with an exoskeleton but the effort pays off big time.
Esquenazi: We had a patient who was a young woman who had been paralyzed for more than 6 years as a result of a trauma to her spine and she actually was able to wear an exoskeleton and for the first time, get up and step forward under her own control, so that was pretty amazing and was able to eventually cross a whole room on her own feet assisted by an exoskeleton.
Pence: And her reaction?
Esquenazi: One of great emotion, one of huge pleasure and satisfaction and gonna translate what she said, which was – one of hope that she would be able to achieve something that was told to of never happen – which was to walk again.
Reed: Researchers believe patients may also receive secondary health benefits from using an exoskeleton.
Gorman: Are they more fit? Do they have more endurance? Do their bowels work better? Because that is a major issue with people with spinal cord injury who sit all day, and so forth – so we’re all interested in those secondary affects of this type of technology. Getting people out of their wheelchairs is inherently a good thing for skin intactness; sitting down all the time puts someone at risk for sores. There is some fairly good evidence, if done regularly, standing will improve bone marrow mineral density especially if sort of early after a spinal cord injury – that’s still preliminary but it is well known that people with spinal injury lose bone strength in their legs.
Pence: However not every spinal cord injury patient is a good candidate for an exoskeleton. Of the 12,500 new cases per year experts say maybe only a quarter of those make good candidates for various reasons. And of that number, perhaps only a thousand worldwide now use the device on a daily basis. Most patients use the exoskeleton as a therapeutic intervention just a few times a week.
Gorman: They are generally designed to be put on with some practice within 5 or 10 minutes but have to realize that people with spinal cord injuries don’t have normal sensation so that there is always concern you don’t want to cause any type of sores or skin breakdown because of such a device.
Pence: Also certain models have been approved by the FDA for home use and require a caregiver to act as a spotter. Then there’s the issue of still having to use crutches so your hands aren’t free and the price tag is fairly hefty; around 35-40 thousand dollars. But for some, that’s a small price to pay to be able to stand again – especially for something as important as your own wedding.
Gorman: Or for their graduation ceremonies or the things that are traditionally done standing – those are big milestones in a person life and if one can participate in those milestones standing up, well that’s a big deal. This technology is continuing to improve, will be hopefully less expensive as time goes on and therefore more accessible. I see that through research and refinement they are becoming safer and we are learning a lot about how to train folks with these devices.
Esquenazi: Probably in the next 10-15 years we’ll see full integration of this kind of devices where you wont have to wear an exoskeleton as such, it’ll be maybe a fabric clothing piece that you wear that has fibers that are electronically alter in sizes so they will work as if they were artificial muscles. But it will be just a garment that has this kind of capacity to generate movement.
Pence: Esquenazi says, even now researchers are zeroing in on a truly bionic interface.
Esquenazi: They are, for example, some experiments being run right now in which people have direct plug in their brain – and I mean it like that, they have a hole in their head that has a plug and they can connect to a computer and have what’s called “Computer Brain Interface” – that allows them to control either a computer or control a device that may for example have them feed themselves or help them hold a phone so they can have a conversation or do other activities that are otherwise impossible to do because they have paralyzed arms.
Dr. Homayoon Kazerooni: We’re using as much as we can to create a better quality of life. I’m confident that a few years from now there will be other researchers and engineers and scientists who will join and make the technology better to a point that in many applications wheelchairs will be replaced.
Pence: That’s Dr. Homayoon Kazerooni, Professor of Mechanical Engineering at the University of California Berkeley, Director of the Berkeley Robotics and Human Engineering Laboratory and founder and Chief Scientist at Berkeley Bionics. Kazerooni envisions breakthroughs in virtually every aspect of the technology in coming years – lighter materials, faster sensors, more clever codes and smaller and longer lasting batteries.
Kazerooni: Unfortunately, science fiction writers and movie makers have created a lot of movies – like Iron Man, like Aliens, whatever there are a lot of robotic devices that are worn by people – and these movies have created an image for people that is beyond realistic, it’s always about aggressive motions about war and fighting, it’s about augmenting physically a person to overcome a war or a sort of conflict. You can jump over buildings, you can go down underwater for 20 seconds and save the girl and fight and kill the other guy – and these are the images that you can see.
Pence: Kazerooni agrees that these movies are entertaining and fun but they don’t inspire him. He’s much more inspired by people who actually need and use this technology for every day living.
Kazerooni: People with mobility issues, elderly, we see children that they are victims of conflict zones, we see people who sort of fall through the crack because they just have some sort of disability, also we see workers who put their bodies into abuse all day long in construction sites, in manufacturing facilities – so these are the people we want to augment. We want to bring bionics to these people; bionics is not about Superman, bionics is not about Iron Man, bionics is not about getting stronger and fight, bionics is about creating better quality of life through engineering, through science. One of my dreams is, for example, to see a person with a spinal cord injury can get up on a plane and walk down the aisle of the plane and go to the bathroom easily and come back and sit – that is what I’m looking at, that would be my Iron Man, that would be my super hero.
Pence: You can learn more about all of our guests and about bionic technology by visiting our website at RadioHealthJournal.net. Our writer/producer this week is Polly Hansen. I’m Reed Pence.
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