Ekso’s Exoskeletons Let Paraplegics Walk, Will Anyone Actually Wear One?

Ekso Bionics builds robotic exoskeletons that can help paraplegics leave their wheelchairs. All CEO Eythor Bender has to do is create a market for a product that no one knew they wanted.

Ekso’s Exoskeletons Let Paraplegics Walk, Will Anyone Actually Wear One?

After six years in a wheelchair, Tamara Mena can walk again. Photo by Gabriela Hasbun

Tamara Mena was 19 years old when she dismissed all hope of ever walking again. Mena was living in San Diego and working toward a degree in hotel management when she and her boyfriend Patrick decided to hit the clubs in Rosarito Beach, just across the Mexican border. Since they didn’t want to risk drinking and driving, they took a cab. They never made it to Mexico.


About 2 miles from their destination, their vehicle slammed into a horse. The impact launched the animal into the air; it landed on top of the cab, crushed the roof to seat level, and killed Patrick and the driver instantly. Mena was paralyzed from the midchest down.

“I wanted to walk,” she says. Graced with tawny hair, high cheekbones, and chocolate-brown eyes, Mena, now 25, is a picture of youthful vitality if you overlook the tracheotomy scar where medics inserted a tube to oxygenate her collapsed lungs after the accident. “I looked into walking with braces, but they sucked the energy right out of me. I met with a doctor about stem-cell treatments, but that was costly and there was no guarantee. I gave up. I had to move on.”

Exoskeletons, says Ekso bionics CEO Bender, will be “the jeans of the future,” streamlined enough to wear in economy class.

Six years after that fateful night, in a nondescript warehouse in Berkeley, California, she is moving on–using her own two legs. She stands on the linoleum floor, supporting herself with a pair of crutches, an expression of quiet determination on her face. The lower two-thirds of her body are enclosed in an aluminum frame attached by Velcro straps to her ankles, calves, thighs, hips, and chest. A physical therapist stands behind her, one hand grasping a handle on the contraption’s rear panel, the other holding a control panel. Each time the therapist presses a button, small electrical motors at the frame’s joints move in a motion that replicates the action of corresponding muscles–one of Mena’s hips swings ahead, the associated knee rises, the foot lifts and then falls to the floor, and she takes a precious step forward.


Mena is a test pilot for Ekso Bionics, a front-runner in robotic exoskeleton technology, which can replace or augment human capabilities. Led by Icelandic CEO Eythor Bender, the company has licensed its technology to Lockheed Martin for military use and sold its initial medical product, the Ekso, to rehabilitation centers throughout the U.S. Bender says the medical market is just the beginning. He envisions robotic frames for industrial workers, like miners, dockers, and construction workers. He imagines that each of us will want an exoskeleton: “the REI Ekso,” recreational outerwear that confers superhuman strength and endurance.

“We’re starting with soldiers and paralyzed people because their needs are great and the opportunity for funding is better,” Bender says. “But you can imagine exoskeletons for workers using tools too heavy to hold for more than a few minutes. And a consumer version for people who want to run a marathon or climb Mount Kilimanjaro.” Exoskeletons, he dreams, will be “the jeans of the future”–practical, fashionable, and streamlined enough to wear in economy class.

First, though, he must get past obstacles that have derailed many a medical-device company. He must convince rehabilitation therapists and wheelchair users that the Ekso is more than a pricey gewgaw. He will need to outdistance competitors, some of whom already have products on the market. Finally, he must persuade the FDA and the insurance industry that paralyzed people need to walk, a proposition that’s controversial even among paraplegics.


NORDIC SPIRIT: CEO Bender thinks exoskeletons could affect industries as diverse as construction and health care. Photo by Gabriela Hasbun

For Mena, the Ekso’s impact has already exceeded expectations. “I just wanted to walk again,” she says. “But once you get up, you realize how meaningful it is to look at people eye to eye and hug someone while you’re standing up. I had forgotten what that felt like. Once you remember, it’s hard to go back to a wheelchair.”

Ekso Bionics’ staff has ballooned from 23 to 68 in the past year, and its Berkeley facility is fit to burst. Past the cramped reception area (which doubles as a customer-service bullpen), it’s Santa’s robotics workshop. The 12,000-square-foot floor is a labyrinth of workbenches, storage bins, and whiteboards covered with electrical diagrams. A yellow gantry–basically a 35-foot girder on trestles–cuts across the floor to protect test pilots like Mena against falling.

A fully assembled Ekso hangs on a rack next to one of the benches, its legs pumping repetitively in test mode. Even without an upper body, it looks shockingly human. Its architecture matches the familiar anatomy of legs and hips; its black aluminum frame (adjustable to wearers of different heights) mimics the bones, its gently whirring electrical motors, the muscles. Its gait falls between a leisurely stroll and a military step as it marches toward the marketplace.


The dream of a wearable robot capable of overcoming the frailties of human anatomy dates back at least to March 1963, when Marvel Comics published its first issue devoted to Anthony Edward “Tony” Stark, a millionaire industrialist who donned a mechanized suit to become the Invincible Iron Man. The U.S. military was thinking along the same line, and six months later, Army engineer Serge J. Zaroodny published a paper entitled “Bumpusher: A Powered Aid to Locomotion.”

Zaroodny’s design kicked off nearly four decades of dubiously productive military investment in the concept. The human body burns calories in proportion to the work it does, but early exoskeletons consumed immense amounts of energy simply standing still. The only solutions were to tether the robot to a wall socket or strap a powerful gasoline engine to its back. Neither option was fit for the battlefield.
A key breakthrough came in 2004. At the University of California, Berkeley, Homayoon Kazerooni, Nathan Harding, and Russ Angold realized that the standard techniques for driving hydraulics were simply too inefficient. A mobile robot required a fresh approach. Their DARPA-funded design shunted weight through its joints into the ground, so it didn’t consume energy at rest, and it used regeneration to take advantage of gravity and recapture expended energy. This allowed the team to cut the electrical cord in favor of battery power. The result was the first practical untethered exoskeleton.

Angold had only military needs in mind until he received a terrible phone call: His brother had broken his back. “I flew to Virginia Beach, where he was in the hospital, and said, ‘We’re going to make exoskeletons to help people walk again,'” he recalls. His brother eventually made a full recovery, and Angold returned to martial applications. But at conferences, the team kept running into doctors interested in a therapeutic exoskeleton.


Recognizing opportunities in two disparate markets, in 2005, Kazerooni, Harding, and Angold formed Ekso Bionics (then called Berkeley Bionics). CEO Bruce Borup came aboard three years later, fresh from a stint with CFC, Inc. magazine’s fastest-growing U.S. defense contractor of 2007. He promptly cut a licensing deal with Lockheed Martin, which would refine, manufacture, and market the olive-drab Human Universal Load Carrier, or HULC, giving Berkeley Bionics a royalty on sales.

Borup’s knowledge of the defense market was indispensable to securing the deal, but he departed soon afterward. To attack the medical market, the company needed a different kind of CEO. It needed Eythor Bender.

In a dreary conference room off the shop floor, eight potential investors gather around a long table laid out with plastic bowls of trail mix and bottles of Snapple. It’s late November 2011 and Eythor Bender–the first syllable of his given name is pronounced like a long A–is looking for a new round of funding to propel the Ekso into the market. His slim frame toned by daily workouts and his graying hair cropped close, Bender leans forward and addresses the group.


“Most bionics companies come from the mechanical world,” he says, his Icelandic accent turning the last word into a cat’s purr. “Here in the Bay Area, we have a convergence of computers, software, sensors, batteries, materials, bioengineering, and the entrepreneurial spirit to do something outrageous. We’re in a strategic location. We have a unique team. We are a tour de force waiting to happen.”

Bender’s triumph-in-the-making currently operates on a $10 million grant from the Defense Department, $7 million from Lockheed Martin to help develop the military product, and $8 million in Series A funding, mostly from angels, notably IronPort cofounder Scott Banister. An additional few million would help ensure a quick start out of the gate. Bender is adamant, though, that the company remain VC free and privately funded until the Ekso is established. Bad experiences at previous companies have convinced him to work with only hands-off investors. “I’ve seen devastating decisions made because of institutions or VCs trying to control the business agenda,” he says.

“An early-stage company that’s doing something so disruptive requires a lot of freedom of movement,” he tells me. In its medical incarnation, the Ekso challenges makers of rehabilitation equipment and, down the line, wheelchairs. As an industrial or consumer product, who knows? Bender feels that the company’s impact on, say, the construction business could be revolutionary. That’s why he wants absolute freedom to discover and serve early adopters that will give the company traction. “It’s like being on a Viking ship in the middle of the ocean,” he says. “You have to smell and feel everything to find your way. You can’t do that with too many people telling you what to do.”


This restless Nordic spirit has animated Bender’s career since he was a child working in his father’s import-export shop in Reykjavik. His maternal grandfather served as Iceland’s minister of sport, and Bender has always integrated business with a commitment to health and fitness. Back in 1995, he was stagnating in a gig at Hewlett-Packard’s medical monitoring division. That’s when Bender left HP and went to work for Ossur, the company that makes the prosthetic limbs used by amputee sprinter
Oscar Pistorius, who won a silver medal in last year’s track-and-field World Championships for South Africa. “It was great to make monitors for hospitals,” he says, “but it is much more interesting to apply technology directly to the body.”

The Center for Spinal Cord Injury Recovery, in Detroit, looks more like a health club than a hospital wing. Part of the Rehabilitation Institute of Michigan (RIM), the facility is a brightly lit atrium filled with exercise balls, parallel bars, and elliptical machines, as well as more exotic devices: racks that let people raise themselves into a standing position, bicycles attached to electrodes that zap muscles into pushing the pedals. The patients are helped out of their chairs to bounce a ball or to stretch on all fours.

“When you learn to walk as a child, it just comes to you,” says Quadriplegic Milewski. “This machine duplicates that to a t.”

RIM has purchased an Ekso, due for delivery in May. Today the staff is working with a trial unit, learning how to fit it to patients, step them around the track that outlines the room’s perimeter, and document the results.


Brendan Milewski, a local firefighter who was hit by falling debris while battling an arsonist’s blaze in 2010, is circling the track. This is his third Ekso session. RIM therapists on either side of him, and one in back, chant, “Crutch, up tall, shift, step. Crutch, up tall, shift, step. Good!” His steps are even and regular, one every two or three seconds. He stops to towel sweat from his face. “I was impressed from the moment I stood up by how effortless the machine is,” he says. “When you learn to walk as a child, it just comes to you. This machine duplicates that to a T.”

Not everyone who wants to strap into an Ekso can use one. Of three first-time test pilots I witnessed at Ekso Bionics’ offices, only one made more than a single traverse along the yellow gantry and back. At 5-foot-1, she just managed to pass the company’s strict requirements for height, weight, strength, and range of motion. The second candidate’s hip joints had stiffened over the years, so she didn’t pass muster. As for the third, her bowel leaked as she was returning from the gantry and she couldn’t bear to continue.

At RIM, all six test pilots have walked successfully. Nonetheless, the Ekso is an odd fit for the center, which emphasizes recovery over functional proficiency. Researchers have found that in patients who retain some motor function, forcing them to actively use a paralyzed limb can forge new neuromuscular connections. “Ekso does the work for you,” says physical therapist Paula Denison, who supported purchasing the unit. “We struggled with whether to buy it.”


The deciding factor was the Ekso’s potential in cases where people have lost all control over their legs–so-called motor-complete injuries. There’s no therapy to bring about recovery in such cases. Moreover, these patients have few options for exercising the lower extremities. Working the legs can be critical to long-term health in a wheelchair, staving off potentially deadly urinary tract infections, skin ulcers, and cardiovascular disease, while promoting bone density, strength, and flexibility. “Because it fills a big gap for people with complete injuries, I do think it will attract business for any rehabilitation facility that buys one,” Denison says.

The medical-benefit question will become critical when Bender starts selling Eksos to individual patients. For now, with a price of $130,000, Eksos are strictly for one-percenters. But even well-to-do customers will seek recompense from insurers, and predictable reimbursement is a prerequisite to selling personal Eksos that retail for $50,000 to $75,000–Bender’s goal for 2014. The iBot wheelchair, which hit the market in 2003, offers a cautionary tale. Designed by Dean Kamen and manufactured by Johnson & Johnson, the iBot offered capabilities like four-wheel drive, the ability to balance on two wheels at standing height, and the agility to climb stairs. One problem: It cost $22,000. Medicare deemed its innovations “not medically necessary” and refused to reimburse more than the $6,000 cost of a conventional powered wheelchair. In 2009, the manufacturer threw in the towel.

Ekso could suffer the same fate if it doesn’t show benefits beyond those afforded by less costly devices such as standing wheelchairs. This is where the health data collected by rehabilitation centers are crucial. The device itself is capable of measuring its own performance in several dimensions; it can track the number of steps taken, which Bender says will help prove that patients actually use it and exercise their heart and limbs.


Of course, the biggest question is whether wheelchair users even want a personal Ekso. People who suffer a spinal-cord injury often reject the notion that they are broken and need to be fixed. “There are millions of people who function fine in a wheelchair,” says marketing VP Karl Gudmundsson. “We can’t frame it like we’re their savior.” Many wheelchair users dismiss exoskeleton technology as too slow and, given the relatively low cost and widespread impact of wheelchair ramps and the like, outrageously expensive. “If I had a pot of money, I’d put it toward things I know will benefit people in the shorter term,” says Peter Axelson, a wheelchair user and engineer whose company, Beneficial Designs, makes sporting equipment adapted for paraplegics.

For now, Ekso Bionics and its competitors have set their sights on the medical market. Denison chose the Ekso over the ReWalk-I from Argo Medical of Israel. The Israeli device, which is in use at several U.S. rehab facilities, does offer capabilities the Ekso can’t match: It can climb stairs and navigate inclines, and its steps are activated by the wearer’s gestures rather than a therapist’s button presses. But other therapists who had used the ReWalk told Denison that it took too long to get patients in and out of it.

New Zealand’s Rex Bionics has sold several exoskeletons outside of the U.S. It is now seeking FDA approval for personal models. Operated by a joystick built into an armrest, Rex doesn’t require arm strength and thus accommodates a wider variety of patient conditions. But some therapists find its gait more akin to “going for a ride” than walking, which limits its therapeutic benefits.


The Ekso, ReWalk, and Rex could be outdistanced by technological breakthroughs. At Vanderbilt University, roboticist Michael Goldfarb has taken advantage of newer batteries, motors, sensors, and manufacturing methods to build a lighter, potentially cheaper exoskeleton that snaps apart to fit in a knapsack. The unit integrates electrical stimulation, prompting leg muscles to contract by applying minute jolts to the wearer’s skin. Goldfarb expects to sign a licensing deal with a major manufacturer as early as this summer. His unit has gotten rave reviews from therapists and patients, but it’s relatively unknown. “We’ve been low-key,” Goldfarb says ruefully. “Ekso Bionics has taken a very high profile.”
And that may make all the difference. In a few short months, Bender’s team has recruited a cadre of attractive ambassadors like Mena, who can make the Ekso seem like a lifestyle choice. He has established beachheads at leading rehab centers, outmaneuvering rivals and building momentum that will make it difficult for upstarts like Goldfarb to overtake him. Most important, Bender has succeeded in positioning the Ekso as the exoskeleton industry’s trailblazer. His vision of a world where Eksos are pervasive in work and play is far more expansive–and compelling–than that of any competitor.

Ekso Bionics’ principals like to compare their invention with Henry Ford’s Model A, brought to market in 1903. “There are all these expensive, low-quantity machines that make great technology demos, and everyone wants to make the Model T,” Nathan Harding says. “Once that happens, the whole thing will break wide open.”


So it’s fitting that the company is preparing to move into the former Ford Motor Co. Assembly Plant in Richmond, California, which has been turned into a trophy office building. On a sunny late-December morning, Bender shows off the company’s new location, an undivided expanse with lofty ceilings and twice the floor space of the current facility. An area along the windowed outer wall may become a test and demonstration space, which he calls “our Apple Store.”

“We’re at a crossroads,” he says. The first Eksos in the U.S. shipped in February, while Europeans will get theirs starting in May. Then it’s time to scale up. “It’s pretty amazing,” he marvels. “We’ll look back and think, Wow, this was a huge milestone. And we have to get through it before we do something more grandiose.”

That larger ambition begins with the personal Ekso in 2014. That model may include Segway-style balance and upgraded ankle joints to handle inclines. The company is proceeding as though it will need to pass the FDA’s most rigorous process, but it has applied for a special classification that could shorten the time and expense to approval.

Bender’s growth strategy hinges on the idea that an exoskeleton is a platform, and that software will eventually adapt the hardware to any task that would benefit from mechanically assisted strength and endurance–from stroke victims relearning to walk to soldiers humping body armor and builders hoisting sacks of concrete, from Junior hiking the wilderness to Grandpa cleaning out the garage. In other words, Bender is out to recalibrate the range of human possibility.

Back at the Berkeley office, Mena, the test pilot who had given up on walking, puts the change in concrete terms. “I mentor patients,” she says. “Sometimes they ask whether they’ll ever walk again. I used to say, ‘There’s no guarantee.’ Now I can say, ‘If the device fits you, you will walk.'”

Bender looks at her with the faintest hint of a smile. “Tamara has requested to walk in high heels,” he says.

“Chunky heels,” she replies. “Not stilettos. We’ll start with chunky heels.”