While the capabilities of prosthetic arms have been getting more impressive over the years, commercial devices generally lack providing any sense of touch. Moreover, attempts to provide a tactile sensation have encountered the problem of producing consistent results in different situations and throughout the user’s entire day.
Now researchers at University of Illinois are reporting in journal Science Robotics on a new system that adjusts the intensity of electrotactile stimulation of prostheses so that users can consistently feel things the same way every time.
Loose electrodes and a build up of sweat during the day are a couple of ways that stimulation can loose its strength. To compensate for this, the new system monitors the actual sensory stimulation that the person using the system is experiencing. When changes are noticed, the system adjusts the intensity so that the final result is what it should be.
All this is very important because while a prosthetic can have great mechanics and lots of power, using it is difficult without a sense of touch. By enabling this sense within prostheses and making it work consistently, the usability of prosthetic devices can be significantly improved.
“Once we get a miniaturized stimulator, we plan on doing more patient testing where they can take it home for an extended period of time and we can evaluate how it feels as they perform activities of daily living. We want our users to be able to reliably feel and hold things as delicate as a child’s hand,” said Aadeel Akhtar, an MD/PhD student at U of Illinois and lead author of the study, said. “This is a step toward making a prosthetic hand that becomes an extension of the body rather than just being another tool.”
Study in journal Science Robotics: Controlling sensation intensity for electrotactile stimulation in human-machine interfaces…