Prosthetics

Until recently, people who lose their limbs or are born without them have been forced to use prosthetics little advanced from the stereotypical wooden peg leg of yore. Today, 60 million people around the world and nearly 2 million in the US live with limb loss. That number in the US is expected to double by 2050, mostly due to the type 2 diabetes epidemic, as well as vascular disease, trauma and cancer. The good news: prosthetics are getting better, smarter and cheaper thanks to ever-increasing AI brainpower and the democratization of 3D manufacturing.

Today, implanted neuroprosthetic devices help restore functionality across a wide range of neurological and behavioral issues, from seizures and Parkinson’s to loss of hearing and sight—and, recently, targeting OCD and obesity. The list of deep brain stimulation (DBS)–treatable conditions will grow exponentially. Within a decade, new neuroprosthetic techniques and interfaces will make it unnecessary to perform surgery to implant these life-saving devices.

BUILDING A BETTER ARTIFICIAL LIMB

A new generation of “smart” prosthetic limbs, designed using 3D modeling tools and made with 3D printers, is on the horizon. These include bionic legs that create an effortless gait by anticipating the movements of wearers by continuously monitoring trajectory in relation to the body and the ground. Some plug directly into human nerve tissue for high-fidelity access to electrical signals and muscle movements, while others use sensors in the prosthetic socket to foster neurological connections.

TrueLimb, a durable, 3D-printed prosthetic arm with more than 30 sensors guiding its bionic functionality, is tailored to a user’s exact size, shape and even skin tone. Myoelectric sensors in BrainRobotics’ prosthetic hands connect to muscles and nerves in residual limbs, converting electrical signals from the brain into precise finger movements or programmed actions. Laurent Frossard, a bionic limb scientist at Australia’s Griffith University, and David Lloyd, a Boston University mechanical engineer, are combining biomechanics and computational modeling to create wearable and noninvasive diagnostic devices that rely on designing a precise “digital twin” of each user’s own unique residuum (residual limb). This allows for virtual design and easier refitting and replacements as improved prostheses become available.