The real ‘bionic man’, Hugh Herr, is not content with creating artificial limbs for the disabled that surpass the performance of natural limbs. He wants to spark a revolution by allowing everyone to use them. By David W. Smith
How much of me can be replaced by synthetics whilst I am still considered a human being?
Once you have a bionic limb which has a high level of function, it becomes cool and sexy even if it doesn’t look like a human shape
Biophysicist Hugh Herr is creating a future in which robotic limbs for amputees are as intoxicatingly cool and sexy as fast cars and the able-bodied strap on bionic devices to run to work at 60mph. The Head of the Biomechatronics Research Group at the MIT Media Lab, Herr has devoted his life to designing devices which allow amputees to live normal lives free of stigma and shame. Through his company, BiOM, he has fitted bionic ankle-foots to around 1,000 people, 400 of them injured soldiers.
The ultimate goal of surpassing human functionality is close to the heart of a man who became a double amputee 32 years ago after a teenage climbing accident. Herr’s first attempts were designed to get him climbing again, but he is now close to producing bionic limbs that anyone could wear, with profound consequences for human mobility.
“We’ve just had an important landmark in my lab,” he said. “We’ve built a robotic structure that attaches to the human leg. We’ve augmented normal human walking so a person with completely normal legs can walk with less energy. We still have some way to go to commercialize the product, but it has profound implications for how we see ourselves as humans.”
Herr is as much philosopher as scientist and loves to muse about the implications of his bionic creations. In the near future, he says, bionic devices will enable all of us to get better at walking, running and lifting things. When that happens, we will abandon cars and run to work. “For mobility tasks where you don’t have cargo, it’s absurd to transport the body by getting in big metal boxes with wheels. It’s environmentally bad and a crazy waste of space in cities. Soon we will have personal flexible mobility suits which you hang up on coat-racks. The architecture of our cities will change. There will be a lot more natural surfaces and a lot less pavement.”
Man or machine?
Herr has some way to go in moulding synthetic materials to human tissue and maintaining levels of comfort. But he predicts that technologies which augment physical and cognitive abilities will help to define the 21st century. Unlike the airplane, car and Smartphone, these technologies will be intimate with our bodies and brains. Technologies implanted inside us will blur the distinction between man and machine.
“Once we get the merging of the synthetic built world and our biological tissues, it’s going to become confusing,” he said. “Is the synthetic part that is fully integrated with my tissues part of who I am? And, if part of me is synthetic, am I still human? And how much of me can be replaced by synthetics whilst I am still considered a human being?”
The futuristic ideas and brilliant inventions of the mature Hugh Herr would have astonished the despairing teachers at his High School in Lancaster, Pennsylvania. They wrote the teen off as an academic no-hoper who only wished to climb and improve his fitness in the gym. “I would do anything I could to get out of the classroom,” he admitted. “If you’d asked me at the age of 17 what ten per cent of a hundred was, I wouldn’t have had a clue. I had no idea what percentages were.”
But Herr’s climbing obsession was an expression of a single-mindedness and fearlessness in pursuit of his goals which was later to make him the leader of the bionic age. By the age of eight, he had scaled the face of the 3,544 metre Mount Temple in the Canadian Rockies. By 17, he was acclaimed as one of the best climbers in the US.
Herr’s climbing feats attracted a fan club that included 20-year old Jeff Batzer. In January, 1982, the pair set out to climb a difficult ice route on Mount Washington, in New Hampshire. Caught in a blizzard, they got lost and spent three nights clinging to each other trying to withstand temperatures of −20 °F (−29 °C). Herr started to hallucinate and was convinced he was going to die. Meanwhile, a rescue party was searching for them and tragedy struck when an avalanche hurled 28-year-old volunteer Albert Dow against a tree killing him instantly.
By the time the two climbers were rescued and airlifted to a local hospital, they had severe frostbite and gangrene threatened to spread throughout Herr’s body. Seven operations failed to repair the blood flow to his legs. At this point, Herr learned about Dow’s death and cursed his own recklessness. After weeks of palliative treatments had failed, Herr’s legs were amputated below the knees. Traumatized by the loss, he cried every other hour for months. In honour of Albert Dow, however, he vowed never to feel self-pity.
Herr was fitted with artificial legs, but he was appalled by the low quality of prosthetics available in 1982. He knew they would never allow him to climb with his former agility. “It was staggering to me that I was given an artificial leg made out of wood and rubber without any computer or actuator in the age of going to the moon, cars and the internet,” he said. “It set me on a trajectory designing first my own limbs and then for others as well.”
Ironically, the climbing-obsessed student who had bummed out of classes was now forced to study how to create prosthetic legs in order to climb again. Having studied metal work at school, Herr had some idea where to begin. But he had to become an autodidact, studying maths textbooks from the local library. Months after the accident, Herr took his acrylic legs and headed for the mountains. Using rock faces as a testing ground, and a bag of tools as implements, he started to sculpt the legs as he climbed. Within a year, he had returned to his pre-accident climbing ability and after two years he exceeded it.
The unprecedented prosthetic feet he created enabled him to stand on small rock edges. Titanium-spiked feet helped him to climb ice walls. The flexible prostheses extended his height from five to eight feet to reach cracks and ledges that had been out of reach for the able-bodied teen. “That experience was profoundly motivating. Not only could I eliminate my disability, but I could go beyond what nature had intended,” he said. “I had some pretty funny reactions from climbing friends. One fellow threatened to cut his own legs off and get artificial ones.”
Searching for perfection
Herr continued to modify his designs, searching for perfection. Realizing he needed more knowledge, he began studying at Millersville University, Pennsylvania in 1985. He fell in love with physics and went on to study for a master’s at MIT in mechanical engineering, then a PhD in biophysics at Harvard, and finally a postdoc back at MIT in biomedical devices. All the while, he was working on his designs for knee joints, ankle joints and knee braces.
Herr’s BiOMs are unlike other artificial legs because they emulate lost muscle function rather than relying on the remaining muscles to propel the leg. They are attached with synthetic skin that moves like real skin. They bend like real joints and flex like real muscles. “A large proportion of MIT studies are about how normal physiologies stand and walk and run. We analyse how muscles interact with skeletons and how they are controlled by the spinal cord. Studies of the human body completely determine the design of the synthetic limb that emulates functionality. I call it stealing from nature,” Herr said.
As well as improving quality of life, the machine precision of the bionic limbs is redefining ideas of human beauty. Herr maintains that once the devices exceed the efficiency of human limbs, they become ‘sexy’. The ugliness of most prosthetic devices, Herr argues, is not a consequence of their unnatural shape, but because they result in a low quality of life. Patients limp and feel tired; chafing produces sores. Eventually, stress on the limbs leads to arthritis and bad backs.
“Beauty has a lot to do with function. Once you have a bionic limb which has a high level of function, it becomes cool and sexy even if it doesn’t look like a human shape,” he said. “In fact, it can be very pleasing for it not to have a human form of beauty but to have it expressed as a machine beauty. A sports car doesn’t look like a beautiful woman or man, but it’s powerful and sexy. There’s no requirement that artificial limbs take on a human beauty. Once you have high functionality, it’s a completely new landscape in terms of social appeal and aesthetics.”
So far, Herr’s research group has developed knee prostheses and ankle-foot exoskeletons for patients suffering from drop foot, as well as the first bionic foot and calf system, called the BiOM. But the development of the limbs comes at a high financial cost. Tens of millions of dollars have been invested in MIT’s research. But although the bionic limbs are far more expensive than conventional prostheses, Herr says there is a more sophisticated way to look at the economic impact, which is to consider the total cost of treating a disabled person over a lifetime. From this standpoint, the prosthesis is a small part of total cost.
“The real cost drivers are the fact that the person can’t work and pay taxes, the fact they need healthcare, homecare, a live-in nurse, or hospitalization. And they need pain medication and surgeries. In the age of bionics, where you can give people back their God-given capability, you end up saving money even though the prosthetic intervention is a lot more expensive than previous interventions that don’t fully repair the human,” he said.
Herr gives the example of a young man from Ohio who lost a leg in an industrial accident at work. He was out of work simply because the conventional prosthesis would not allow him to stand up and walk around without undue pain and discomfort to his tissues.
“We fitted him with a bionic limb and a week later he called his boss and said ‘I’m coming back to work’. The actuary data shows that if you don’t get a young person back to work in about nine months, they will usually be lost to drugs and alcohol and typically cost the state US$5 million-US$8 million over a lifetime. So, yes, the bionic limb is more expensive, but it can save millions of dollars for just one individual and trillions for the nation. When true bionics replicates human biology it’s a win for the patient and it’s also a win for the payer.”
The problem, Herr said is that there are few examples of real bionics. But he predicts that will change in the next decade, or two, as different disciplines cooperate to find solutions. “So many subjects are relevant to the bionic age. We are seeing the blending of mechanical engineering, with electrical engineering and neuroscience, but also fashion design and art are relevant,” he said. “We are now at the point of history where there’s enough maturity in the disciplines that we are seeing real examples of bionics.”