A High-School Student Invented a Mind-Controlled Prosthetic Arm

When Benjamin Choi was in the third grade, he watched a “60 Minutes” segment on an invented mind-controlled prosthesis. Tiny sensors were implanted into the motor cortex of the brain of a patient who operated a robotic arm with her thoughts alone. Choi loved the idea.

In 2020, Choi, a Virginia tenth-grader, had plenty of spare time. The laboratory where he had expected to spend the summer researching aluminum fuels had closed. However, the documentary he had seen years ago had stayed with him, and he used his time to create a less invasive prosthetic arm.

Choi Designed and Invented the Arm with a $75 3D Printer

Choi independently designed and invented the first iteration of his robotic arm using his sister’s $75 3-D printer and some fishing line, in a makeshift laboratory on a ping-pong table in his basement (where he sometimes worked for 16 hours a day!) Choi printed the arm in tiny bits and bolted and rubber-banded them together because the printer could not produce objects longer than 4.7 inches. It took roughly 30 hours to print the document. This prototype functioned utilizing brain wave data and head motions, and Choi provided online instructions for building your own.

Participation in competitive robotics at the elementary, middle, and high school levels, as well as multiple trips to the world championships, provided him with some prior expertise in robot construction and programming. Beginning in the ninth grade, he taught himself the programming languages Python and C++ by viewing tutorials on the programming website Stack Overflow.

Only $300 to Produce???

After more than seventy-five design revisions, Choi’s non-invasive, mind-controlled robotic arm is invented and constructed from engineering-grade materials that can handle loads of up to four tons. It analyses a user’s brain waves using an algorithm driven by artificial intelligence (AI). It only costs roughly $300 to produce, which is a substantial discount compared to what is currently available. A simpler, body-powered prosthesis for the upper limb costs approximately $7,000. The incredibly sophisticated, full-arm Modular Prosthetic Limb, which contains 26 joints, hundreds of sensors, and can curl up to 45 pounds, costs approximately $500,000 in 2015. This invented prosthesis, when combined with a surgical procedure to reroute the nerves that originally controlled the arm, enables patients to control the limb with their thoughts and even sense texture.

In the United States, an estimated 2 million people have lost a limb, and approximately 185,000 amputations occur annually. According to the World Health Organization, only one in ten persons who require assistive devices, such as prostheses and orthoses, have access to them due to “high cost” and “lack of knowledge, availability, trained personnel, policy, and funding.”

The prosthetic arm invented by Choi uses electroencephalography, or EEG, to avoid the invasive procedures employed by a conventional prosthesis. EEG devices monitor the electrical activity of the brain using sensors positioned on the head. They are frequently used to diagnose epilepsy and other neurological problems.