Victims of the Boston Marathon bombing who lost limbs face a long and intense physical and emotional recovery, part of which may be adapting to prosthetic limbs. Recent advances in prosthetic technologies have greatly improved the quality and precision of artificial limbs, however, including devices that can be controlled with the mind and provide sensory feedback.
Yesterday, WBEZ spoke to a number of Chicago-area researchers about advances in prosthetics, including University of Chicago neuroscientist Sliman Bensmaia. He’s working on a national research project funded by DARPA called Revolutionizing Prosthetics that is working to develop prosthetics that can simulate the feeling of touch in upper arm prosthetics:
“Without it everything that we would do would be extremely effortful, clumsy and slow,” said Bensmaia. For example, limbs with sensation would allow amputees to closely control grip; without that control, it can be more practical to use a high-tech hook than a prosthetic hand. But there’s another benefit to the new technology Bensmaia is working on.
“We feel our own limb as part of ourselves,” said Bensmaia. Which is why some have compared the sensation of losing a limb to losing a loved one. By developing sensory limbs patients could feel more connected to the prosthesis itself. The project plans to test-run its sensory prosthetics on real people within a year.
I spoke to Bensmaia in December about the work in his lab to understand how the sense of touch works. One of their studies showed how sensors in the skin respond to minute vibrations produced by textures that correspond to neural impulses in the brain, much like the way vibrations from sound produce the sensation of hearing. Reproducing these vibrations could be one way to replicate the tense of touch in a prosthetic arm.
Sensory feedback in such devices is important, and so is the ability to control them with greater precision. Earlier this week I also wrote about the work that Nicholas Hatsopoulos, another UChicago neuroscientist, is doing to improve the performance of artificial limbs by interpreting neural signals to anticipate future movements.
Losing a limb is a traumatic experience under any circumstance, but these kinds of advancements are helping to build more useful and natural-feeling prosthetic options for patients.