Robotic hand prosthetics offer amputees some promise, but they often fail to work well if the amputee’s nerve activity is limited. A lot depends on how well the patients’ nerves can regrow and how much of the arms and hands are intact.
The good news is that the University of Michigan (UM) has developed a robotic hand that seems like something out of a science fiction movie. Wired recently profiled the development of the robotic hand, which uses “muscle grafts to amplify nerve signals—allowing amputees to control [the] new prosthetic with incredible precision.”
The novelty of the UM robotic procedure, according to co-developer Paul Cederna, is using the “nerves’ proclivity for growth.” Dr. Cederna and his coworkers take “small pieces of muscle and surgically wrap them around nerve endings in the residual limb.” This way, the nerves “innervate” with the tissue of the muscle (and don’t ball up), which greatly improves the electrical signals from the nerves – which in turn helps give the robotic hand finer control.
The hardware is formally called DEKA, after DEKA Research and Development. DEKA invented the robotic hand. The team affectionately calls it “Luke’s hand” after Luke Skywalker from Star Wars.
The benefits of the new hardware and procedure complement each other
The new procedure helps eliminate “phantom” and neuroma pain because it treats the end of the nerves. It also amplifies the small remaining nerve signals with the muscle.
Dr. Cederna’s team also adds electrodes to the muscle. As a result of the procedure, the nerve signals are 100 times stronger than “before the nerves grew into the muscle.” Muscle grafts are used instead of skin grafts because motor nerves go into the muscle but not into skin.
Based on experiments with four subjects so far, “the nerves that control the thumb interacted with this new muscle just as they would if the person still had their thumb.”
The results indicate that the signals show that the robotic hand is helping on a finger-by-finger (and thumb) basis. The medical team uses algorithms to help train the hand what to do. Another big benefit, so far, is that amputees need much less training to learn how to use the robotic prosthetic. One amputee was even able close zippers, a fine motor manipulation.
At this time, amputees can only use the robotic hand at the lab where the computer is. The hand isn’t ready to be used at home or at work. The hope, though, is that the robotic hand will allow wearers to just think about what movement they want to make instead of learning and relearning.
At Bailey & Greer, PLLC, our Memphis catastrophic injury lawyers understand how devastating losing a hand, foot, limb, or any part of the body can be. We fight aggressively to hold wrongdoers accountable. We work with your doctors to understand your immediate pain and your long-term medical condition. We represent accident victims in Memphis, Jackson, and across Western Tennessee. To schedule an appointment, call us at 901-475-7434 or contact us online.