Prosthetic hands have come a long way, but many are still too unwieldy and impractical for everyday use. Beyond being incapable of a natural hand’s dexterity, most prosthetics can’t offer neurological feedback to the user, thus rendering tactile or kinesthetic sensation impossible. But thanks to a program called DeTOP, a new type of prosthetic is on the horizon: A bionic hand fused to the user’s bone and nervous system, offering unprecedented range and sensation.
DeTOP, short for “dexterous transradial osseointegrated prosthesis,” is a collaboration between research organizations in Sweden, Italy, Switzerland, and the United Kingdom. Since they began working together in 2018, the organizations have sought to create a prosthetic limb that doesn’t just sense texture and pressure but also reproduces the level of dexterity found in a natural hand. DeTOP created its first operational prototype in 2019; shortly after, it began working with a Swedish woman whose lower arm had been dismembered in a farming accident two decades prior. This woman would become DeTOP’s first bionic hand candidate.
The October cover story for Science Robotics details the prototype’s success over the past four years. The woman, identified as Karin, has reportedly been able to use the bionic hand to perform 80% of a natural hand’s functions. It’s a significant improvement over her former circumstances, marked by reduced mobility and near-constant phantom limb pain.
“It felt like I constantly had my hand in a meat grinder, which created a high level of stress, and I had to take high doses of various painkillers,” Karin said in a statement for Scuola Superiore Sant’Anna, an Italian university involved in DeTOP. She added that conventional prosthetics weren’t comfortable or practical enough to be worthwhile. “For me, this research has meant a lot, as it has given me a better life.”
Before she could start using DeTOP’s bionic hand, Karin had to complete a rehabilitation program that helped her forearm bones—the radius and ulna—regain strength. (Bones can weaken following partial amputations, as they’re less frequently used.) She also had to practice commanding her missing hand using virtual reality. Afterward, the bionic hand was fused with Karin’s bones and electrically connected with her nervous system. The electrodes implanted within Karin's forearm and connected to the bionic hand allow her to control each finger and experience pressure and texture.
According to the data published in Science Robotics, Karin’s mobility and overall quality of life have improved after receiving the bionic hand. Her phantom pain, limb pain, and work- and sleep-related complications have decreased significantly.
Though it’s unclear whether DeTOP plans to iterate on its first operational bionic hand, the program’s achievements could easily inspire a new wave of improved prosthetics for amputees.
