October 05 | 2018
If New Metal Legs Let You Run 20 Miles/Hour, Would You Amputate Your Own?
Tyler Clites builds human cyborgs. After graduating from Harvard in 2014 with a B.S. in Biomedical and Mechanical Engineering, Tyler earned his PhD in 2018 from the Harvard/MIT program in Health Sciences and Technology. As a postdoc in the Biomechatronics Group (Professor Hugh Herr, MIT Media Lab), his current research focuses on the development of novel techniques for limb amputation surgery, with the goal of improving the neural and mechanical interfaces between persons with amputation and their prosthetic devices. He is pursuing a career in academia, where he hopes to explore applications in which surgical and mechatronic design can be leveraged together in new bionic systems for physical rehabilitation and human augmentation.
A patient with below-knee AMI amputation walks up the stairs.
(Photo credit: Matthew Orr, STAT News)
"Here's a question for you," I say to our dinner guests, dodging a knowing glance from my wife. "Imagine a future in which you could surgically replace your legs with robotic substitutes that had all the functionality and sensation of their biological counterparts. Let's say these new legs would allow you to run all day at 20 miles per hour without getting tired. Would you have the surgery?"
Why are we so married to the arbitrary distinction between rehabilitating and augmenting?
Like most people I pose this question to, our guests respond with some variation on the theme of "no way"; the idea of undergoing a surgical procedure with the sole purpose of augmenting performance beyond traditional human limits borders on the unthinkable.
"Would your answer change if you had arthritis in your knees?" This is where things get interesting. People think differently about intervention when injury or illness is involved. The idea of a major surgery becomes more tractable to us in the setting of rehabilitation.
Consider the simplistic example of human walking speed. The average human walks at a baseline three miles per hour. If someone is only able to walk at one mile per hour, we do everything we can to increase their walking ability. However, to take a person who is already able to walk at three miles per hour and surgically alter their body so that they can walk twice as fast seems, to us, unreasonable.
What fascinates me about this is that the three-mile-per-hour baseline is set by arbitrary limitations of the healthy human body. If we ignore this reference point altogether, and consider that each case simply offers an improvement in walking ability, the line between augmentation and rehabilitation all but disappears. Why, then, are we so married to this arbitrary distinction between rehabilitating and augmenting? What makes us hold so tightly to baseline human function?
Where We Stand Now
As the functionality of advanced prosthetic devices continues to increase at an astounding rate, questions like these are becoming more relevant. Experimental prostheses, intended for the rehabilitation of people with amputation, are now able to replicate the motions of biological limbs with high fidelity. Neural interfacing technologies enable a person with amputation to control these devices with their brain and nervous system. Before long, synthetic body parts will outperform biological ones.
Our approach allows people to not only control a prosthesis with their brain, but also to feel its movements as if it were their own limb.
Against this backdrop, my colleagues and I developed a methodology to improve the connection between the biological body and a synthetic limb. Our approach, known as the agonist-antagonist myoneural interface ("AMI" for short), enables us to reflect joint movement sensations from a prosthetic limb onto the human nervous system. In other words, the AMI allows people to not only control a prosthesis with their brain, but also to feel its movements as if it were their own limb. The AMI involves a reimagining of the amputation surgery, so that the resultant residual limb is better suited to interact with a neurally-controlled prosthesis. In addition to increasing functionality, the AMI was designed with the primary goal of enabling adoption of a prosthetic limb as part of a patient's physical identity (known as "embodiment").
Early results have been remarkable. Patients with below-knee AMI amputation are better able to control an experimental prosthetic leg, compared to people who had their legs amputated in the traditional way. In addition, the AMI patients show increased evidence of embodiment. They identify with the device, and describe feeling as though it is part of them, part of self.
Where We're Going
True embodiment of robotic devices has the potential to fundamentally alter humankind's relationship with the built world. Throughout history, humans have excelled as tool builders. We innovate in ways that allow us to design and augment the world around us. However, tools for augmentation are typically external to our body identity; there is a clean line drawn between smart phone and self. As we advance our ability to integrate synthetic systems with physical identity, humanity will have the capacity to sculpt that very identity, rather than just the world in which it exists.
For this potential to be realized, we will need to let go of our reservations about surgery for augmentation. In reality, this shift has already begun. Consider the approximately 17.5 million surgical and minimally invasive cosmetic procedures performed in the United States in 2017 alone. Many of these represent patients with no demonstrated medical need, who have opted to undergo a surgical procedure for the sole purpose of synthetically enhancing their body. The ethical basis for such a procedure is built on the individual perception that the benefits of that procedure outweigh its costs.
At present, it seems absurd that amputation would ever reach this point. However, as robotic technology improves and becomes more integrated with self, the balance of cost and benefit will shift, lending a new perspective on what now seems like an unfathomable decision to electively amputate a healthy limb. When this barrier is crossed, we will collide head-on with the question of whether it is acceptable for a person to "upgrade" such an essential part of their body.
At a societal level, the potential benefits of physical augmentation are far-reaching. The world of robotic limb augmentation will be a world of experienced surgeons whose hands are perfectly steady, firefighters whose legs allow them to kick through walls, and athletes who never again have to worry about injury. It will be a world in which a teenage boy and his grandmother embark together on a four-hour sprint through the woods, for the sheer joy of it. It will be a world in which the human experience is fundamentally enriched, because our bodies, which play such a defining role in that experience, are truly malleable.
This is not to say that such societal benefits stand without potential costs. One justifiable concern is the misuse of augmentative technologies. We are all quite familiar with the proverbial supervillain whose nervous system has been fused to that of an all-powerful robot.
The world of robotic limb augmentation will be a world of experienced surgeons whose hands are perfectly steady.
In reality, misuse is likely to be both subtler and more insidious than this. As with all new technology, careful legislation will be necessary to work against those who would hijack physical augmentations for violent or oppressive purposes. It will also be important to ensure broad access to these technologies, to protect against further socioeconomic stratification. This particular issue is helped by the tendency of the cost of a technology to scale inversely with market size. It is my hope that when robotic augmentations are as ubiquitous as cell phones, the technology will serve to equalize, rather than to stratify.
In our future bodies, when we as a society decide that the benefits of augmentation outweigh the costs, it will no longer matter whether the base materials that make us up are biological or synthetic. When our AMI patients are connected to their experimental prosthesis, it is irrelevant to them that the leg is made of metal and carbon fiber; to them, it is simply their leg. After our first patient wore the experimental prosthesis for the first time, he sent me an email that provides a look at the immense possibility the future holds:
What transpired is still slowly sinking in. I keep trying to describe the sensation to people. Then this morning my daughter asked me if I felt like a cyborg. The answer was, "No, I felt like I had a foot."
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Tyler Clites builds human cyborgs. After graduating from Harvard in 2014 with a B.S. in Biomedical and Mechanical Engineering, Tyler earned his PhD in 2018 from the Harvard/MIT program in Health Sciences and Technology. As a postdoc in the Biomechatronics Group (Professor Hugh Herr, MIT Media Lab), his current research focuses on the development of novel techniques for limb amputation surgery, with the goal of improving the neural and mechanical interfaces between persons with amputation and their prosthetic devices. He is pursuing a career in academia, where he hopes to explore applications in which surgical and mechatronic design can be leveraged together in new bionic systems for physical rehabilitation and human augmentation.
July 23 | 2024
Here's how one doctor overcame extraordinary odds to help create the birth control pill
National Science Foundation
Dr. Percy Julian had so many personal and professional obstacles throughout his life, it’s amazing he was able to accomplish anything at all. But this hidden figure not only overcame these incredible obstacles, he also laid the foundation for the creation of the birth control pill.
Julian’s first obstacle was growing up in the Jim Crow-era south in the early part of the twentieth century, where racial segregation kept many African-Americans out of schools, libraries, parks, restaurants, and more. Despite limited opportunities and education, Julian was accepted to DePauw University in Indiana, where he majored in chemistry. But in college, Julian encountered another obstacle: he wasn’t allowed to stay in DePauw’s student housing because of segregation. Julian found lodging in an off-campus boarding house that refused to serve him meals. To pay for his room, board, and food, Julian waited tables and fired furnaces while he studied chemistry full-time. Incredibly, he graduated in 1920 as valedictorian of his class.
After graduation, Julian landed a fellowship at Harvard University to study chemistry—but here, Julian ran into yet another obstacle. Harvard thought that white students would resent being taught by Julian, an African-American man, so they withdrew his teaching assistantship. Julian instead decided to complete his PhD at the University of Vienna in Austria. When he did, he became one of the first African Americans to ever receive a PhD in chemistry.
Julian received offers for professorships, fellowships, and jobs throughout the 1930s, due to his impressive qualifications—but these offers were almost always revoked when schools or potential employers found out Julian was black. In one instance, Julian was offered a job at the Institute of Paper Chemistory in Appleton, Wisconsin—but Appleton, like many cities in the United States at the time, was known as a “sundown town,” which meant that black people weren’t allowed to be there after dark. As a result, Julian lost the job.
During this time, Julian became an expert at synthesis, which is the process of turning one substance into another through a series of planned chemical reactions. Julian synthesized a plant compound called physostigmine, which would later become a treatment for an eye disease called glaucoma.
In 1936, Julian was finally able to land—and keep—a job at Glidden, and there he found a way to extract soybean protein. This was used to produce a fire-retardant foam used in fire extinguishers to smother oil and gasoline fires aboard ships and aircraft carriers, and it ended up saving the lives of thousands of soldiers during World War II.
At Glidden, Julian found a way to synthesize human sex hormones such as progesterone, estrogen, and testosterone, from plants. This was a hugely profitable discovery for his company—but it also meant that clinicians now had huge quantities of these hormones, making hormone therapy cheaper and easier to come by. His work also laid the foundation for the creation of hormonal birth control: Without the ability to synthesize these hormones, hormonal birth control would not exist.
Julian left Glidden in the 1950s and formed his own company, called Julian Laboratories, outside of Chicago, where he manufactured steroids and conducted his own research. The company turned profitable within a year, but even so Julian’s obstacles weren’t over. In 1950 and 1951, Julian’s home was firebombed and attacked with dynamite, with his family inside. Julian often had to sit out on the front porch of his home with a shotgun to protect his family from violence.
But despite years of racism and violence, Julian’s story has a happy ending. Julian’s family was eventually welcomed into the neighborhood and protected from future attacks (Julian’s daughter lives there to this day). Julian then became one of the country’s first black millionaires when he sold his company in the 1960s.
When Julian passed away at the age of 76, he had more than 130 chemical patents to his name and left behind a body of work that benefits people to this day.
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June 14 | 2024
Therapies for Healthy Aging with Dr. Alexandra Bause
Sabine van Erp / Pixabay
My guest today is Dr. Alexandra Bause, a biologist who has dedicated her career to advancing health, medicine and healthier human lifespans. Dr. Bause co-founded a company called Apollo Health Ventures in 2017. Currently a venture partner at Apollo, she's immersed in the discoveries underway in Apollo’s Venture Lab while the company focuses on assembling a team of investors to support progress. Dr. Bause and Apollo Health Ventures say that biotech is at “an inflection point” and is set to become a driver of important change and economic value.
Previously, Dr. Bause worked at the Boston Consulting Group in its healthcare practice specializing in biopharma strategy, among other priorities
She did her PhD studies at Harvard Medical School focusing on molecular mechanisms that contribute to cellular aging, and she’s also a trained pharmacist
In the episode, we talk about the present and future of therapeutics that could increase people’s spans of health, the benefits of certain lifestyle practice, the best use of electronic wearables for these purposes, and much more.
Dr. Bause is at the forefront of developing interventions that target the aging process with the aim of ensuring that all of us can have healthier, more productive lifespans.
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Matt Fuchs is the host of the Making Sense of Science podcast and served previously as the editor-in-chief of Leaps.org. He writes as a contributor to the Washington Post, and his articles have also appeared in the New York Times, WIRED, Nautilus Magazine, Fortune Magazine and TIME Magazine. Follow him @fuchswriter.