After completing undergraduate and graduate programs at the Keio Faculty of Science and Technology, Endo went on to work in MIT Media Lab’s Biomechatronics Group and is now venturing into the world of prosthetics engineering.
I initially chose to attend Keio because my father and brother both studied here. In particular, my brother had done research under then Assistant Professor Takashi Maeno in the Department of Mechanical Engineering, which I think had a considerable influence on my decision. My interest in research started in 2000 when Honda released its humanoid robot ASIMO. I remember how amazing it seemed and how excited I was. ASIMO made me feel like there was potential for robots to make a difference in society and, following in my brother’s footsteps, I decided to work on bipedal humanoid robots in Prof. Maeno’s lab.
-Your move from robotics to prosthetics research had to do with a high school classmate who had developed bone cancer.
That’s right. He had total knee replacement surgery, which eventually led to him amputating that leg above the knee. That’s when he began using a prosthetic. At the time, I had been studying bipedal robots because I thought they would have a positive impact on the world, but I regretted the fact that my research could do nothing to help someone as close as a classmate. I started looking for ways that I could help him through my work, and that search led me to prosthetics research. I chose to study at MIT in 2005 after completing my master's program at Keio because I wanted to study under Professor Hugh Herr, who heads the Biomechatronics group at the MIT Media Lab. He himself is a double amputee and a user of prostheses but remains an active rock climber using limbs of his own creation. He was inspiring on both an academic and human level, and I knew that I wanted to study with him if I could.
Master’s programs in the United States are different from Japan in that there are many more classes to take. With my background in mechanical engineering, I struggled with the computer science classes that were outside of my field. Looking back now, though, I feel like it was probably a good thing that I was able to study computer science from the ground up. And to be honest, my English wasn’t very good either, but having spent so many long days in class or studying, I ended up learning the language, though somewhat reluctantly. [laughs]
-Your experience as a prosthetics engineer goes back to your time at MIT.
Correct. I began my research career in the United States in a rather dark place, armed with this kind of grim determination that I had to do something to help my classmate who had lost his leg and was fighting for his life. But through my work at the MIT Media Lab, I realized that it was the most interesting and inspiring research I could be doing. Researching technologies to support people with disabilities was extremely rewarding, and I became more and more excited the more I worked. At the same time, I realized that people with disabilities don’t need our pity and are the same as everyone else. They lead normal lives, and in some cases, they are even more capable than non-disabled people.
While at MIT, I was surprised to see South African sprinter Oscar Pistorius win a gold medal in the 2008 Summer Paralympic Games in Beijing. Disability aside, he looked amazing as he ran regardless of the fact that he had two prosthetic legs. After that success, Pistorius filed an appeal with the Court of Arbitration for Sport to be able to compete at the Olympics using prosthetics, which resulted in his successful participation at the 2012 Summer Olympics in London. The Japanese media didn’t cover his story much, but it got a lot of attention in the United States. Pistorius ended up being eliminated in the semi-finals, but his strong performance as the first double amputee to compete in the Olympics had a profound impact on people. But with ever-improving records being set by para-athletes, more people are starting to think that prosthetics may be giving them an unfair advantage.
-After returning to Japan, you were a researcher at Sony Computer Science Laboratories (Sony CSL) and started your own business in 2014 to research and develop prosthetics for elite athletes.
Prof. Hiroaki Kitano, the director of Sony CSL, invited me to come work with him after hearing about my research on prosthetic legs. I had known Prof. Kitano since my time doing research at the Graduate School of Science and Technology. At Sony CSL, I was given free rein to do research, but I gradually began to realize that starting my own business was the best way to achieve what I wanted to accomplish. I wanted to develop prosthetic legs for athletes who could win medals at the Tokyo Olympics and Paralympics. To do that, I needed a team that included not only engineers like myself but also athletes and trainers as well. I kept my position at Sony CSL while I launched Xiborg Inc. together with Dai Tamesue, a former Olympic athlete and Japanese record holder for the Men’s 400-meter hurdle. Currently, our team consists of three Japanese para-athletes—Jun Haruta, Keita Sato, and Mikio Ikeda—as well as one American, Jarryd Wallace, a T44* Paralympic sprinter who won the 100-meter event at American nationals in 2016.
*T44 is a disability sport classification for disability athletics, applying to "Single below knee amputation or an athlete who can walk with moderately reduced function in one or both legs."
-How are your preparations for the Tokyo Olympic and Paralympic Games?
Of course, we are preparing for the games, adjusting each athlete’s prosthetic leg according to the way they run. I hope that the Japanese people who witness the abilities of para-athletes at this year’s Paralympic Games will start thinking about removing the barriers between whom we see as healthy and disabled. In terms of competitive ability, only about 10% of performance depends on prostheses. After all, the athletes themselves are the driving force in any competition. That's why I’m focused, not on the Tokyo Games, but on the 2024 Olympics and Paralympics in Paris. My current goal over the next four years is to train para-athletes who are destined to become national heroes in France. Just the other day, I traveled to Paris to see the city and the current state of transportation. As a medieval city, it is not nearly as disability-friendly as somewhere like Tokyo. I’m paying close attention to how the city changes as it gears up for 2024.
That’s right. Mr. Ototake is a Japanese writer who was born without arms and legs, and in this project he attempts to walk bipedally wearing a robotic prosthetic equipped with an ankle motor that we developed at Sony CSL. I think a lot of people felt a kind of excitement as they watched Mr. Ototake trying so hard to walk with prosthetics. But impressing people is not why Mr. Ototake and I are working on this project. In fact, an electric wheelchair is much more comfortable and convenient for Mr. Ototake, who is missing both legs below the thigh. There is no need for him to walk on two legs the way a non-disabled person does. The ulterior motive of this project is to spark a discussion on the differences that exist between the non-disabled and people with disabilities, especially in Japan, which is gearing up to host the Paralympic Games. I’m hoping that our business and our technology will create an opportunity to change Japanese people’s awareness of people with disabilities. I thought that we could have a more significant impact if someone like Mr. Ototake, who wields enormous social influence, were involved.
-We’ve heard that you are also involved in international aid through your prosthetic work.
In 2008, during my time at MIT, I went to India for an internship and became involved with NGOs that provided free prosthetic legs to the less fortunate. It is said that there are 20 to 30 million people in India who need prosthetic legs. Since many of them live in low-income rural areas and cannot benefit from prosthetics technology, we have been trying to make prosthetic legs more affordable. The prosthetics we make for athletes and people like Mr. Ototake would cost a few million yen—tens of thousands of dollars—if commercially available, but these prosthetics would cost just a few thousand yen, or tens of dollars. And it is the power of technology that allows us to reduce these costs. These activities led me to Hiroyuki Hane, a Japanese national coach who trains runners with prosthetic legs in Laos. Mr. Hane himself is a para-athlete and a man I respect with all my heart. I’m hoping to help out wherever I can by sharing my experience and technology.
-You’re based at Shin-toyosu Brillia Running Stadium, where you’ve started a "Blade Library."
I started this project in 2017 to share the joys of what we call "blade running" with prosthesis users. An athlete's prosthetic leg spring is made of the finest carbon fiber reinforced plastic—the same material used in aircraft construction—which can cost thousands of dollars apiece. This kind of cost means that there is little to no chance for the next generation of prosthetic runners to try one out. In addition to the 24 leg springs available, the Blade Library also offers a wide variety of parts for knee fittings and joints, so children and adults can easily try them on for just 500 yen. Installation and adjustment require the help of prosthesis orthotics, but if you can replace them yourself, you can come and run whenever you like. Whenever I see a child who’s running along happily, I know that we did the right thing starting this library. I am determined to design a world where amputees never have to give a second thought before going on a run, and I intend to begin by tackling the Japanese social security system.
-Could you say a few final words to current students?
As an engineer, I would advise my younger peers not to believe everything adults tell you. We're living through a technological revolution, facing unprecedented situations that go unsolved because the older generation is unable to adapt. I can barely keep up myself! You are the next generation and you are the ones who can cope with these changing times. Be confident and ambitious—trailblaze a new path of your own. I look forward to seeing what you can accomplish!
-Thank you for your time.
OTOTAKE PROJECT 2018
CEO & Prosthetics Engineer, Xiborg Inc.
Ken Endo graduated from the Keio Faculty of Science and Engineering in 2001. After completing a master’s program at the Graduate School of Science and Technology in 2003, Endo went to the US, where he worked on analyzing human physical ability and developing below-knee prostheses at the Biomechatronics Group within the MIT Media Lab, where he received his Ph.D. in 2012. After returning to Japan, he became an associate researcher at Sony Computer Science Laboratories Inc. (Sony CSL). In 2014, he established Xiborg Inc. to develop prosthetic legs for athletes. In 2012, Endo was chosen as one of MIT Technology Review’s 35 Innovators Under 35, and in 2014 was selected for the World Economic Forum’s Young Global Leaders.
*This article originally appeared in the 2019 autumn edition (No. 304) of Juku.
*All affiliations and titles are those at the time of publishing.