Evoked haptic sensations in the hand via non-invasive proximal nerve stimulation

Abstract

Our findings demonstrated the capabilities of our transcutaneous stimulation method. Subjects were able to perceive spatially distinct sensations with graded magnitudes that emulated tapping and holding sensation in their hands. The elicitation of haptic sensations in the phantom hand of an amputee is a significant step in the development of our stimulation method, and provides insight into the future adaptation and implementation of prostheses with non-invasive sensory feedback to the users.

Evoked Haptic Sensation in the Hand With Concurrent Non-Invasive Nerve Stimulation

“…Spatially distinct haptic sensations with controllable intensity can be induced in the hand by activating different axons of the median and ulnar nerves. Similar results have been shown in both able-bodied individuals and an amputee through proximal nerve bundle stimulation [23], although a study on the stimulation of distal nerve branch failed to show sensations of phantom digits [24], potentially due to subtle cortical reorganization after digit amputation [25].…”

“…Limitations of this study include the lack of amputee subjects, analysis at different current amplitudes, and the absence of the evaluation of sensory adaptation that may occur over continuous stimulation. The use of neurologically-intact individuals to represent the haptic sensation perceived by amputees has been supported by results shown previously [23]. Namely, controllable levels of haptic sensation evoked were found to be similar in both amputee and neurologically-intact individuals, which suggests that the results from intact individuals can be representative and translatable to amputees.…”

“…This form of stimulation was termed as the single stimulation. A constant pulse frequency of 150 Hz and pulse width of 200 μs per phase were used throughout the experiment, and these parameters were selected based on an earlier study [23]. The current amplitude was dependent on the subjects, their anatomical characteristics, and electrode grid placement.…”

“…All subjects had no known neurological disorders. An earlier study has shown that intact subjects demonstrated similar haptic sensations in response to nerve stimulation as in amputated individuals [23]. Each subject gave informed consent via protocols approved by the Institutional Review Board of the University of North Carolina at Chapel Hill.…”

Phantom limb pain: peripheral neuromodulatory and neuroprosthetic approaches to treatment

“…The participant reported improvements in both severity and quality of PLP. Other studies are currently evaluating transcutaneous sensory feedback in neuroprostheses, but none reported effects on PLP . Although most studies focus on functional outcomes of sensory restoration for closed‐loop prostheses, there have been a number of qualitative reports of reductions in PLP.…”