Hugh Herr's bionic revolution: when technology becomes part of us

I'm acutely aware of the impact of good, well-designed technologies on humans. And I'm also very aware when there's a design mistake and a device doesn't work well, the negative impact on humans. I'm extremely motivated to put technology out in the world that truly benefits humans.

This is Made for Us, the show where we explore how intentional design can help create a world that works better for everyone. I'm your host, Tosin Suleiman. Today, my guest is Hugh Herr, MIT professor and co-director of the Yang Center for Bionics. Named the leader of the bionic age by Time magazine, his work focuses on creating bionic limbs that emulate the function of natural limbs. But growing up, he had a different obsession. A passionate rock climber from the age of 7, he was considered a child prodigy, and by his teens was one of the top climbers in the United States. In this conversation, he tells me how a mountain climbing accident at the age of 17 changed his life's mission and made him realize the power of technology to rehabilitate and even extend human capabilities. We talk about the big breakthroughs that have come out of his lab at MIT, including the first bionic leg completely controlled by the brain, and he shares how he's working towards a world where there's equal access to prostheses. Here's our conversation.

Hugh Herr. I'm a professor at MIT. I direct the Biomechatronics Group in the MIT Media Lab. I also co-direct the K. Lisa Yang Center for Bionics at MIT.

So let's imagine you're on a plane, you're sitting next to a random stranger, and they ask you what you do. How would you describe your work to them?

We develop technology, bionic technology that attaches to the body or is implanted inside the body. that augments human physicality. So the technology can be used for assistance for persons with some type of limb condition, like amputation or paralysis, or the technology could be used to augment human capability beyond innate physiological levels.

So it's been really fascinating learning about the mission of your lab and reading your recent papers. You clearly spend more time than most people thinking about the future. So I thought we could begin there. Could you paint a picture of the world that you and your team are working towards?

My team at MIT, we're focused on a future world in which technology is so beautifully integrated into human physiology that the technology itself, the design itself, becomes part of the person and ceases to be a mere tool. Like a hammer is a tool. So what we're discovering in the field is when you beautifully connect electromechanics with human physiology, enabling a person to think and to affect the mechatronics and to actually feel the mechatronics as a natural percept, the mechatronics becomes part of the person's body. When you ask them, what is your body? The individual that has this bionic bidirectionality with their nervous system states that it's part of them. It's part of their body schema. So that deep level of integration leading to embodiment is a future goalpost that we're working towards.

And so what does that look like, say, you know, 20, 25 years from now? What can we expect the world to look like?

Yeah, so we're in the business of rebuilding bodies, not just more and more powerful AI-driven technology. So our work is an example where we put humanity into technology, where humanity is in control, and where it's crystal clear that humanity's being serviced by the technology that's truly in benefit of humanity. What we're doing is trying to mitigate unwanted limitation, unwanted disability in individuals. So a person that has paralysis and wants to run, wants to dance, we're working towards a world where that can be possible. Imagine a future world in which any human limitation that's unwanted by the individual can be mitigated or eliminated.

And you had an interesting prediction about the Olympics. Can you share what that was?

Yeah. So, uh, what's interesting, I predict that will occur in this 21st century is there'll be many technologies invented that augment human physicality. So you can imagine exoskeletons that allow persons to run faster than innate biology can allow. You can imagine technology that allows humans to climb mountains better than ever before. So just as we had the invention of the bicycle that led to cycling, we're going to see all these human augmentation technologies that lead to completely new sports, power running, power climbing, power swimming. This new bionics era will unleash very exciting stories in the domain of humans and sport. If the Paralympics does not impede technological progress, if the athletes through this century are allowed to use the latest and greatest, then I predict the Paralympics will be far more exciting than the Olympics. The Olympics will be like, oh, that's what boring regular bodies can do. And the Paralympics will be this human machine. bionic augmentation that'll be very exciting. So I predict that as a spectator sport, the Olympics will decline and the Paralympics will increase in population.

That's a fascinating vision. And this vision for the future is also deeply inspired by your own personal journey. This is something that's personal for you, and I'd like for listeners to get a sense of where you're coming from and what put you on this path. So let's go back to when you were growing up. You had another, I guess, singular obsession back then, and I understand it wasn't school. What was your main preoccupation at the time and what were your ambitions?

Yeah, I started climbing at the tender age of 7. I started mountain climbing and absolutely fell in love with the activity or sport. And through my tweens and teenage years, I was obsessed with climbing and By the age of 15, 16, 17, I was one of the top climbers in the United States. I was so obsessed with the extreme sport of climbing that I did everything to get out of the classroom. Went to vocational school simply because it afforded me 3 hours for lunch break where I would go climbing mountains. So when I was 17, I was in a mountain climbing accident. and suffered severe frostbite. And after months of struggle, my medical team could not save my biological tissues, and both my legs were amputated just below my knees. So I've been using prosthetic limbs or bionics for a very long time, since 1982.

And could you talk about what the rehabilitation process was like? You know, first of all, there must have been lots of different emotions swirling through your head, you know, when you had the accident. How did you process it all?

You know, lying in the hospital after my legs were amputated, I really did not know what to expect of my future. I think I had met one human being with a prosthesis ever in my life. And, you know, remarkably, I still wanted to climb mountains. That was— the accident didn't change my passions. I wanted to get back on the horse and return to the vertical world of rock and ice climbing. And my father at the time said, you know, if you want to do that, if that's your dream, make it happen. I'm certain it's possible. And fortunately, he was very, very correct. So it turns out through design, I was able to fabricate prostheses that enabled me to climb at a very, very high level. In fact, About a year and a half after my legs were amputated, I was climbing better than I had achieved before the accident, which surprised everyone, including me.

I can imagine. And I wanted to ask you about your first pair of artificial limbs. What do you remember most about the conversation with, with the doctor, and what was it actually like walking in them?

Yeah, the first prostheses provided to me were passive. The prosthesis was not computer controlled, had no sensors, no muscle-like motors or actuators. They were simply crude passive devices made of wood and foam and composite. I was just dumbfounded. In the age of space travel, like, how could this be? It was really at that time that I began focusing on design and That led to a life's mission to improve technologies like prostheses to enable people to do what they want to do in their life, to have bodies that they seek without unwanted limitations. So yeah, that was a really pivotal time because I had an early success via design and augmenting my own body in climbing. That really inspired me. And I began as a young man imagining a future world of advanced bionics that would enable people to run faster than biological legs are capable. You know, maybe even prostheses wouldn't even look human-like. Maybe they would have wings and people could fly with using that part of their body. So yeah, that was a very important time. in my life that really crystallized what I wanted to do with my future and the focus of even my current work.

So the fact that you were able to design your own prosthesis to enable you to climb and you were able to reach an elite level within a year and a half made you realize what you could do to help other people who had had a similar experience.

Yeah, I mean, I realized firsthand that technology has the power to heal, to rehabilitate, And even sometimes extend human capability beyond biological innate levels. So yeah, I fell in love with invention, with innovation, and the power of technology to really extend who we are as humans.

So back to MIT and the lab, and this is where you and your team are building the future that you described earlier. In terms of who could potentially benefit, can you give a sense of the scale of this and how many people around the world could be impacted by your research?

My group at MIT, we're focused not only on expanding human knowledge through publication, but we're also focused on actually setting the foundations of new technologies that ultimately lead to products that directly benefit persons in need. So there's a fairly robust, long history in my lab doing the preliminary design work that ultimately leads to a product. We've— out of the lab has come artificial knees, computer-controlled artificial knees, ankles, surgical techniques, exoskeletons, many different products. And that's exciting. I think top engineering schools should both produce product and knowledge, of course. Only producing knowledge and not working with how ideas are translated to the public, I think, is a mistake.

And so can you take us inside the lab? Just describe what it's like there and what might be happening on any given day.

The lab is quite cluttered and messy, and I think that's a good sign. There's a lot of interesting equipment and artifacts in every nook and cranny that we often on a typical day bring in a person with amputation or paralysis and they under strict regulatory guidance, we, we test new technologies. It could be a new robotic hand controlled by the brain or a foot or a knee or a new exoskeleton. So we do lots of building, we do lots of testing on human subjects, and then we kind of close the loop as we learn more empirically that feeds back and we change our models and our designs and we rebuild and we go through this iterative process.

Can you talk about, you know, what have been the key areas of focus that have led to your biggest and most surprising breakthroughs?

Yeah. So in 2014, I made a decision. To not focus on robotics and AI and rather have a tremendous focus on how do we communicate between the human brain and machines. So the neural interface that will allow a person to control artificial muscles, electric motors through thought and actually feel movement, feel touch when their mechatronics are interacting with them. The reason I made that decision is, again, embodiment. So if the field continues to push only robotics and AI, we can restore natural movement, natural dynamics to people with amputation, for example. It's only a matter of time. But since the person's brain isn't creating the movement, isn't in control, the person will feel they're being driven. They'll feel like they're using a powerful tool. They're on kind of on top of a powerful tool. They won't feel that the tool is them. The technology is part of their their schema. So only by linking the brain, in my view, can we have a deep integration with electromechanics where we can actually rebuild a person's body instead of giving them a powerful tool. So that's that's been the goal, and we made tremendous progress. We've We're now able to link mechatronics directly to the skeleton with osseointegration, and we can also link it to muscles and nerves, allowing agency and ownership over the mechatronics. So it's been, been an exciting few years.

And when you talked about people feeling like they're being driven as opposed to being the ones in control, is that something that, you know, presumably that you can relate to? Has that been your experience?

Yeah, my current prosthesis that where the fundamental design was done by my lab many years ago, the prosthesis is called Empower by Ottobock. The Empower currently is what I call intrinsically controlled. So all the sensing and computation is on the device itself. So my nervous system is not driving the mechatronics. So again, they're very powerful devices, remarkable technologies. But I think to achieve a higher level of sophistication, again, we need to link the mechatronics to the skeleton and to muscles and nerves, and that to give the user this sense of that their whole body has been restored. Yeah, I'll never forget the first time I walked on a robotic prosthesis. It felt mechatronic and mechanical and I was being pushed and driven. It's a fun feeling, but again, it felt like I was in the backseat of the car and someone else was driving. And what we want is we want the human to be in the front seat and driving, and there's not a differentiation between the car and their body. That's what we want.

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We had 2 fairly recent important publications that have come out of the lab. About a, just over a year ago, we had a paper in Nature Medicine of the first bionic leg that restores natural movements, where the limb is completely controlled by the brain, which is remarkable. So the basic functionality of the limb came from the spinal cord and the central brain. Not from a robotic algorithm. For that innovation, we invented years ago a new surgical technique and interface called the Agonist-Antagonist Myeloneural Interface. The acronym is AMI. So when a limb is amputated, we connect muscles together in agonist-antagonist natural pairs so they can move dynamically as if the natural limb still exists. So when my legs I have the old style of surgical intervention. In my legs, my muscles are not connected mechanically, so I can fire my muscles, but they can't move dynamically in pairs. And what I feel is I, I feel my foot, but I can't move my foot ankle. It's like my foot is in cement. So what we've done is connected muscles in natural pairings. And after the surgery, the person thinks and moves their phantom limb. And the muscles physically move and send to the brain information of length, speed, and force. And the person actually feels the full dynamic range of their phantom. We then put sensors and we record from those muscles and decode the signals to control the biomedic prosthetic joint to move as the person intends. So not only do they feel the movement, But when they look down, they, they see the robot moving exactly as they intended. So that's one critical invention. Another is we're marrying that AMI procedure with osseointegration. So osseointegration is typically using titanium. It's a shaft that goes through the skin membrane into the residual bone. And in time with loading, the bone integrates into the titanium. And it forms as a mechanical connection. So when you load the prosthesis, there's loads going through the titanium right into the residual bone. A new type of osseointegration allows fine-wine electrical leads through the titanium into electrodes in the body that we put on those AMI muscles. So combining all these technologies together, in a recent paper in Science, We're able to show really versatile restored motor capability in persons with above-knee amputation. So we're just adding more and more surgical regenerative implant technologies, control systems, and really having this tissue-integrated prosthetic paradigm that restores not only movement and sensations, but embodiment. Wow.

So each innovation sort of builds, they sort of build on each other. Is the goal that in the future anyone who wants to will be able to access these really advanced prosthetics?

Yeah, absolutely. The soft tissue work, I mentioned the AMI, that's already a product, if you will. So at Brigham and Women's Hospital, where my colleague Matthew Carty works, he can perform the AMI amputation procedure now as standard of practice without even an IRB. So it's now an officially innovated, fully available surgical technique. We expect the technique to become available in many hospitals throughout the world. When new techniques and technologies are tested on humans, within a research setting. There's an institutional review board that has to review the experiments, approve them, make sure there's safety and ethics as part of that process. When a technology has gone through full experimentation, has had full regulatory oversight, it could then be made available commercially to thousands or hundreds of thousands of patients around the world. We're always very, very focused on, for important innovations, to translate them from the bench in the lab to, to the outside world where people can benefit.

So you're clearly pushing the boundaries of technology. Is this the first step towards creating cyborgs?

Yeah, absolutely. My definition of cyborg is that bidirectionality. So you have a mechatronic system and you have the human nervous system. To connect them bidirectionally, where a person can think, input information into the mechatronic system, into the computers, and also from sensors on the mechatronics, that information's put into the human nervous system. That bidirectionality I define as cyborg. So to have, for a human to have agency, to think and have volitional control over a design construct and to feel the construct as part of self is a cyborg interaction. So yeah, absolutely. As we close the loop, if you will, in the lab, we're creating future cyborgs.

And what does this mean for you and the Like the prosthetic devices that you are currently using?

It's interesting. And throughout my history, I've always had the very best prostheses because I'm developing advances, but I currently do not. And to get these most advanced neural systems, I would have to go under the knife, which I intend to do in the next several years to get these surgical constructs and implants. So I too can think and Move my mechatronic ankles. I can't wait. It'll be extraordinary.

Amazing. So I understand that a lot of what's developed in the lab, that you often sort of test the prototypes yourself. Your former student, David Sanger, wrote in his book that by offering your body for your team to experiment on, you enabled them to do something profound. Can you share the philosophy behind that?

The fact that I used BionX is beneficial for a few reasons. One is I'm acutely aware of the impact of good, well-designed technologies on humans. And I'm also very aware when there's a design mistake and a device doesn't work well, the negative impact on humans. I'm extremely motivated to get it right. To put technology out in the world that truly benefits humans. Another reason it's a benefit is, as you stated, in lab, when I'm able, I'm often the first guinea pig. So I test the devices and because I understand the devices, I understand the prototypes and I can feel it, I'm able to debug the prototype faster than anyone. So I can say, oh, change that gain or do this. So that is a superpower that I have. It's fantastic.

And I wonder how you cope with failure. I'm just curious if there have been instances where you were convinced something would work and it didn't, or perhaps other people told you you'd fail.

I don't have perhaps— I don't have a typical view of quote-unquote failure. I don't even use that term. To me, it's about exploration and adventure. When an experiment produces something that's unexpected, when it doesn't work, in my view, that should be celebrated because you're one step closer, pun intended, towards a solution. So when something surprising happens, that's how a lot of great science is done, by accident. So that's not a failure. I mean, to be successful, you know, we have to take extraordinary risk and we have to be willing to take risk and be surprised by the world or we won't have success. So to me, it's about a creative lab, a creative institution allows for risk and allows for exploration. It's essential.

So another challenge is access and affordability. I was just wondering what proportion of the addressable market can afford these advanced prosthetic limbs.

Yeah, the fraction of, of the population that can gain access to really advanced bionics is far too small. It's a very critical problem. We do everything we can to develop new technology that will fall into standard reimbursement strategies, but sometimes, of course, that's not the case and we have to Convince the payer, either government payers or insurance, private insurance, that they should cover the new technology. And that's a multi-year effort and very challenging. That's kind of in highly developed, technologically developed nations. In parts of the world, getting any prosthesis is challenging. Parts of the world that are poor, the individuals and the citizens don't have, often don't have access. to prostheses at all. So we have an effort in Western Africa, in Sierra Leone, Africa, to actually make robust and strengthen the orthotics and prosthetics sector within the country. And that's a very, very exciting, exciting effort. We have a multi-prong effort improving supply chain, infrastructure, technology, and education. So all 4 of those pillars we call the SITE, an acronym SITE, are critical to really establishing an O&P sector that's sustainable. So we're first implementing it in Sierra Leone, and when we're successful, we want to translate our SITE model to other parts of the world. But it's just a note, it's unacceptable, of course, That only certain technologically advanced nations should have access to essential life-firming prostheses. In other parts of the world, there's little to no access. We have to work towards a world where there's uniformity and access.

And I think you've visited Sierra Leone yourself. Can you say more about the challenge that they're facing and, you know, how many people could ultimately be impacted?

When our effort began, there was one working trained clinician in the entire country and upwards of estimates are approximately 30,000 people with major limb loss, many individuals from the brutal civil war that ended in 2002. So, you know, one clinician for 30,000 people, completely unacceptable. When we arrived, much fewer than 1% of that population had Prosthesis at all. And often that 1%, the prosthetic components were 20 years old, 30 years old, and the prosthetic device is simply falling, falling apart. Building a healthy orthotics and prosthetics sector in a place like Sierra Leone is, is non-trivial. It's supply chain. It's very hard to ship into the country. The infrastructure was very Unstable when we arrived. And then technology. So there's many examples in places like Sierra Leone where unsafe technology is being used. There might be a project on 3D printing where the material degrades in the presence of water. I mean, there's a monsoon in Sierra Leone. It's unsafe. So we, we're, we want to create a high standard of, of very, only very safe technologies are used. Then finally, education. Again, there's only one working clinician, so we're now training 11 new clinicians for the nation, and we intend to expand that to 25 new clinicians. It's really cool when you train a young person on how to build a brace or orthosis or a prosthesis. They're young and they, they'll, they'll work until they're 60, 70 years old. So the impact you can have is enormous through education.

And I heard you say that you would need to raise about $100 million to realize this vision.

$10 million for Sierra Leone would create a sustainable model. $100 million, we can scale it across many, many countries. So yeah, it's interesting. We can go to generous philanthropic donors and One donor may care about Mexico and another India. We can sort of raise those funds and repeat our model in many regions of the world.

And so when you look back at your younger self when you were 17 and where you are today, what surprises you most about the journey?

I'm surprised how far we've come. I'm very pleasantly surprised. It's amazing what human creativity and a lot of energy can produce. It's super fun. And we're at such a critical mass now where the next few years will be very exciting because we have all these different fields coming together and coalescing to a level of bionics that we've only seen in Hollywood films. So it's going to be a really exciting time moving forward.

Well, Hugh, it's been a pleasure having you on the show. Thank you so much for taking the time to do this.

It's been a pleasure and honor to, to speak with you today.

That was MIT Professor Hugh Herr. If you'd like to learn more, I've included links in the show notes to the Biomechatronics Group and the Yang Center for Bionics at MIT. Thanks for joining me on this episode of Made for Us. Please do take a moment to share your feedback in the survey, which is also linked in the show notes. I'm Tosin Suleiman. See you next time.