Recent research published in Science Translational Medicine showed peripheral nerve interfaces implanted in two participants with upper limb amputation provided stable, natural touch sensation in their hands for more than a year.
Using implanted peripheral nerve cuff electrodes that did not penetrate the nerve, two participants had electrical stimulation produce touch perceptions at many locations on the phantom hand with repeatable, stable response for 16 months and 24 months.
Through patterned stimulation intensity, participants reported a natural sensation without paresthesia and different patterns produced different types of sensory perception at the same location. Study results showed participants felt tactile perceptions described as natural tapping, constant pressure, light moving touch and vibration. Researchers also found size of the percept area was controlled by changing the average stimulation intensity, while sensation strength was controlled by changing stimulation frequency. Patients experienced improved ability to control grasping strength of the prosthesis with artificial touch sensation which allowed better manipulation of delicate objects.
“The work reactivates areas of the brain that produce the sense of touch. When the hand [was] lost, the inputs that switched on these areas were lost,” Dustin Tyler, PhD, an associate professor of biomedical engineering at Case Western Reserve and associate director of the Advanced Platform Technology Center at the Cleveland VA, stated in a press release. “The sense of touch is one of the ways we interact with objects around us. Our goal is not just to restore function, but to build a reconnection to the world. This is long-lasting, chronic restoration of sensation over multiple points across the hand.”
For more information:
Tan DW. Sci Transl Med. 2014;doi:10.1126/scitranslmed.3008669.
Disclosure: See the full study for all authors’ relevant financial disclosures.
