For a young boy, his dream of helping others access what seemed out of reach, was all sparked by an episode of “60 Minutes.” More than a decade ago, Benjamin Choi, then a third-grader, watched the news program and saw something fascinating: a mind-controlled prosthetic arm.

The woman, who was using the arm, had gone through surgery to receive an implant that allowed her to move the arm, using only her thoughts. Choi said the science reminded him of “Star Wars”. “I was really, really amazed at the time because this technology was so impressive,” he told The Smithsonian.

But I was also alarmed that they require this really risky open brain surgery. And they’re so inaccessible, costing in the hundreds of thousands of dollars.”

Benjamin Choi works on a prosthetic arm that he designed. Photo by Society for Science

But 10 years later, when the Covid-19 pandemic first hit, Choi was in a place where he suddenly had more than enough time to try and build his own prosthetic arm. His summer internship was canceled, and he was stuck at home. 

Using his family’s basement as a lab, he began working, sometimes for nearly 16 hours a day. He used a ping-pong table as his work surface, and used his sister’s 3D printer, and some fishing line, for the first prototype.

Because the printer was small, it only built pieces that were no more than 4.7 inches. Printing dozens of tiny pieces, Choi then fastened the arm together with bolts and rubber bands. The first version took 30 hours to print and used brain waves and head gestures to work. He then shared the instructions online for others to use for free.

The teenager had worked on robotics all throughout his school career, participating in championships multiple times. Now, with more than 75 design changes, Choi’s prosthetic arm has top-notch materials that can handle up to 4 tons of weight. It uses artificial intelligence to read brain waves.

And the best part? It only costs $300 to make. An average price of a typical arm prosthetic is $7,000 for a very basic version. Full-motion prosthetics can run as high as $500,000. Choi has managed to make a prosthetic that not only functions like a high-end model, but is affordable for anyone to purchase. His arm makes use of EEG (electroencephalography), which copies the brain’s electric waves through sensors on the head.

Benjamin Choi poses with the prosthetic arm he created. Photo by Society for Science

“The more you use it, the more it figures out specifically how you think, what your brain wave patterns are, until the accuracy really increases significantly for you over time,” Choi said.

For all of his hard work, his invention landed him in the Top 40 of the U.S. Regeneron Science Talent Search. “It means a lot to me to see that my work is recognized like this,” Choi said. “I’m definitely very grateful to be a finalist.”

According to the World Health Organization, there are at least 2 million people missing a limb in the United States, with more than 185,000 amputations yearly. The WHO says that only 1 in 10 have access to the devices they need, due to “high cost and a lack of awareness, availability, trained personnel, policy and financing.” Watch how Choi came up with his amazing new design.

Source: The Smithsonian