Researchers are studying several approaches to provide prosthetic hands with the capability of “sensory feedback,” according to results presented in the June issue of Plastic and Reconstructive Surgery.
Paul S. Cederna, MD, of the University of Michigan, Ann Arbor, and colleagues studied a group of recent and emerging techniques that can provide some sensation while enabling amputees to experience more natural, intuitive use. The review focuses on technologies that create “sensory interfaces” with peripheral nerves in order to produce the sensation of touch. Cederna and colleagues believe touch capabilities would lessen the cognitive burden of upper limb amputation while also providing psychological benefits for amputees, according to a press release.
Among the techniques reviewed is sensory substitution, a technique that substitutes one type of sensation, such as the application of vibration to the residual limb, for another type — the feeling of touch from the prosthesis. Cederna and colleagues also reviewed various types of implanted neural interfaces. The interfaces connect electrodes placed in or around the nerves to sensors on the prosthesis. The process allows patients to feel characteristics of an object including stiffness, shape and size, as well as to control fine-motor movements without the use of visual cues.
The researchers also studied targeted muscle reinnervation, which uses transferred nerves to provide sensation to intact muscles and overlying skin, and an experimental technique called sensory regenerative peripheral nerve interface, which uses a “bioartificial interface” to transfer sensory signals directly from a prosthetic sensor to the remaining nerve, according to the release.
“The ultimate goal is to develop a prosthesis that closely mimics the natural limb, both in its ability to perform complex motor commands and to elicit conscious sensation,” Cederna and colleagues wrote in the review, adding that the new technologies “represent the wave of the future, paving the way to more intuitive prosthetic control through sensory feedback.”
Cederna PS, et al. Plast Reconstr Surg. 2015;doi:10.1097/PRS.0000000000001289.