via University of Pittsburgh
Imagine tying your shoes or taking a sip of coffee or cracking an egg but without any feeling in your hand. That’s life for users of even the most advanced prosthetic arms.
Although it’s possible to simulate touch by stimulating the remaining nerves in the stump after an amputation, such a surgery is highly complex and individualized. But according to a new study from the University of Pittsburgh’s Rehab Neural Engineering Labs, spinal cord stimulators commonly used to relieve chronic pain could provide a straightforward and universal method for adding sensory feedback to a prosthetic arm.
For this study, published today in eLife, four amputees received spinal stimulators, which, when turned on, create the illusion of sensations in the missing arm.
“What’s unique about this work is that we’re using devices that are already implanted in 50,000 people a year for pain — physicians in every major medical center across the country know how to do these surgical procedures — and we get similar results to highly specialized devices and procedures,” said study senior author Lee Fisher, Ph.D., assistant professor of physical medicine and rehabilitation, University of Pittsburgh School of Medicine.
The strings of implanted spinal electrodes, which Fisher describes as about the size and shape of “fat spaghetti noodles,” run along the spinal cord, where they sit slightly to one side, atop the same nerve roots that would normally transmit sensations from the arm. Since it’s a spinal cord implant, even a person with a shoulder-level amputation can use this device.
Fisher’s team sent electrical pulses through different spots in the implanted electrodes, one at a time, while participants used a tablet to report what they were feeling and where.
All the participants experienced sensations somewhere on their missing arm or hand, and they indicated the extent of the area affected by drawing on a blank human form. Three participants reported feelings localized to a single finger or part of the palm.
“I was pretty surprised at how small the area of these sensations were that people were reporting,” Fisher said. “That’s important because we want to generate sensations only where the prosthetic limb is making contact with objects.”
When asked to describe not just where but how the stimulation felt, all four participants reported feeling natural sensations, such as touch and pressure, though these feelings often were mixed with decidedly artificial sensations, such as tingling, buzzing or prickling.
Although some degree of electrode migration is inevitable in the first few days after the leads are implanted, Fisher’s team found that the electrodes, and the sensations they generated, mostly stayed put across the month-long duration of the experiment. That’s important for the ultimate goal of creating a prosthetic arm that provides sensory feedback to the user.
“Stability of these devices is really critical,” Fisher said. “If the electrodes are moving around, that’s going to change what a person feels when we stimulate.”
The next big challenges are to design spinal stimulators that can be fully implanted rather than connecting to a stimulator outside the body and to demonstrate that the sensory feedback can help to improve the control of a prosthetic hand during functional tasks like tying shoes or holding an egg without accidentally crushing it. Shrinking the size of the contacts — the parts of the electrode where current comes out — is another priority. That might allow users to experience even more localized sensations.
“Our goal here wasn’t to develop the final device that someone would use permanently,” Fisher said. “Mostly we wanted to demonstrate the possibility that something like this could work.”
The Latest Updates from Bing News & Google News
Go deeper with Bing News on:
- Dynamic temporal modulation of somatosensory processing during reachingon January 20, 2021 at 4:00 pm
Here, we examine whether somatosensory processing throughout a goal-directed movement is constantly suppressed or dynamically tuned so that online feedback processing is enhanced at critical moments ...
- Sensory Launches Free VoiceHub Development Platformon January 19, 2021 at 11:42 am
Sensory has moved forward with the official release of its new VoiceHub solution, after anouncing a beta trial in October ...
- Highschool Start-Up Launches Virtual Reality System to Help Mitigate Autistic Meltdownson January 18, 2021 at 4:04 pm
Cognality VR LLC creates calming virtual reality scenes that helps individuals with autism manage the effect of meltdowns ...
- Home gardeners test tomato varieties for University of Floridaon January 18, 2021 at 4:41 am
“Our goal is to get feedback on the performance and consumer acceptability ... The varieties will also be evaluated in the usual manner, with volunteers at the university’s Sensory Lab in Gainesville.
- These haptic feedback VR gloves are changing virtual reality – here's howon January 15, 2021 at 9:51 am
Haptic feedback could be the next frontier for immersive VR experiences, and the new SenseGlove Nova VR gloves make a firm stride in that direction, bringing us closer than ever to realistic ...
Go deeper with Google Headlines on:
Go deeper with Bing News on:
Spinal cord stimulators
- New treatment helps patients with a spinal cord injuryon January 28, 2021 at 12:06 am
Spinal cord injuries disrupt the mechanism by which our bodies regulate blood pressure. A team of Swiss and Canadian scientists have developed ...
- Neuroscience: Treating hypotension induced by spinal cord injurieson January 27, 2021 at 6:48 pm
A spinal stimulation treatment that restores blood pressure maintenance after spinal cord injury in rodents and non-human primates is demonstrated in Nature this week. Preliminary investigations in a ...
- ‘Pacemaker for the spine:’ Study improves quality of life for Calgary doctor with spinal injuryon January 27, 2021 at 6:22 pm
Dr. Richi Gill of Calgary broke his neck in a freak accident on a boogie board during a family vacation in Hawaii three years ago.
- ‘Pacemaker for the spine:’ Study improves quality of life for man with spinal injuryon January 27, 2021 at 1:04 pm
CALGARY - A paralyzed Alberta doctor has gone from performing surgery to being a test subject in a research study that could help those suffering ...
- Research finds blood pressure can be controlled without drugs after spinal cord injuryon January 27, 2021 at 12:04 pm
Dr. Richi Gill, MD, is back at work, able to enjoy time with his family in the evening and get a good night's sleep, thanks to research. Three years ago, Gill broke his neck in a boogie board accident ...