Chronic intraneural electrical stimulation for prosthetic sensory feedback

The functionality of prosthetic limbs is restricted by the limited availability of sensory feedback. The goal of the present research is the development of a multichannel microelectrode array for the presentation of sensory information directly to the sensory afferent neurons of the transected peripheral nerve of an amputee. Intraneural electrode arrays were developed and implanted in the proximal stump of the transected sciatic nerve in 18 New Zealand White rabbits and monitored for chronic functionality. Several novel nerve regeneration implant designs employing axially oriented Platinum/Iridium wire arrays and regeneration tubes were explored. Somatosensory evoked potentials were monitored via chronically implanted epidural electrodes. A behavioral technique was used to monitor stimulus perception; an electrical stimulus was delivered to the implanted nerve followed by an airpuff to the eye with monitoring of the resultant eye-blink reflex. In this classical conditioning technique, the rabbits associate the two stimuli such that electrical stimulation of the sciatic nerve without an airpuff elicits an eye-blink. Neurophysiological and behavioral tests have demonstrated chronic single channel electrode functionality for greater than 2 years in implanted animals. This research supports the possible viability of an implanted neuroelectric interface in providing chronic sensory feedback in humans.