“Long-term stability of stimulating spiral nerve cuff electrodes on human peripheral nerves”

Abstract

BackgroundElectrical stimulation of the peripheral nerves has been shown to be effective in restoring sensory and motor functions in the lower and upper extremities. This neural stimulation can be applied via non-penetrating spiral nerve cuff electrodes, though minimal information has been published regarding their long-term performance for multiple years after implantation.MethodsSince 2005, 14 human volunteers with cervical or thoracic spinal cord injuries, or upper limb amputation, were chronically implanted with a total of 50 spiral nerve cuff electrodes on 10 different nerves (mean time post-implant 6.7 ± 3.1 years). The primary outcome measures utilized in this study were muscle recruitment curves, charge thresholds, and percent overlap of recruited motor unit populations.ResultsIn the eight recipients still actively involved in research studies, 44/45 of the spiral contacts were still functional. In four participants regularly studied over the course of 1 month to 10.4 years, the charge thresholds of the majority of individual contacts remained stable over time. The four participants with spiral cuffs on their femoral nerves were all able to generate sufficient moment to keep the knees locked during standing after 2–4.5 years. The dorsiflexion moment produced by all four fibular nerve cuffs in the active participants exceeded the value required to prevent foot drop, but no tibial nerve cuffs were able to meet the plantarflexion moment that occurs during push-off at a normal walking speed. The selectivity of two multi-contact spiral cuffs was examined and both were still highly selective for different motor unit populations for up to 6.3 years after implantation.ConclusionsThe spiral nerve cuffs examined remain functional in motor and sensory neuroprostheses for 2–11 years after implantation. They exhibit stable charge thresholds, clinically relevant recruitment properties, and functional muscle selectivity. Non-penetrating spiral nerve cuff electrodes appear to be a suitable option for long-term clinical use on human peripheral nerves in implanted neuroprostheses.

Implantable Neural Interfaces and Wearable Tactile Systems for Bidirectional Neuroprosthetics Systems

“…To mitigate this effect, it is strongly suggested to closely bound the cuff to the nerve . However the use of extra neural devices allows to avoid the suture to secure the device to the nerve, thus improving the mechanical coupling …”

“…In regard to electrical stimulation performance, the use of extra neural devices provides mainly the access of the closest fascicles to the epineurium, preventing the activation of central axon populations without the simultaneous activation of nearby fascicles. However this behavior can be avoided by involving multiple current sources and steer the current between active sites . Taghipour‐Farshi et al simulated that the use of tripolar electrical stimulation resulted in a restricted activation of a more localized region within a nerve trunk compared to a cuff with monopolar configuration.…”

“…Comparison among different strategies of stimulation of PNS to evoke tactile percepts. Parameters that have been considered are: i) number of subjects (S) and implant duration; ii) type of implanted electrode, number of channels, nerve target; iii) impedance measurement; iv) type of stimulation pattern; v) threshold charge/current over time; vi) …”

Long-Term Home-Use of Sensory-Motor-Integrated Bidirectional Bionic Prosthetic Arms Promotes Functional, Perceptual, and Cognitive Changes

“…These methods have proven effective in patient performance of tasks such as precise force generation (De Nunzio et al, 2017), force discrimination , stiffness discrimination Witteveen et al, 2014), stimuli localization (Antfolk et al, 2013), and multi-site sensory discrimination (Antfolk et al, 2013). Other approaches are also being pursued, including electrical stimulation of peripheral nerves (e.g., Christie et al, 2017), electrocutaneous stimulation (e.g., Paredes et al, 2015), and direct cortical stimulation of the primary somatosensory cortex (e.g., Tabot et al, 2013;Hiremath et al, 2017).…”

Classification of naturally evoked compound action potentials in peripheral nerve spatiotemporal recordings

“…Intraneural electrodes that penetrate the nerve, such as longitudinal or transverse intrafascicular electrodes or microelectrode arrays, are able to selectively record neural activity and are increasingly being translated to human studies [10,19,20] but still struggle to demonstrate viability for stable chronic recordings. Extraneural electrodes, such as nerve cuffs or flat interface nerve electrodes (FINEs), have been shown to be stable for chronic implantation in humans for recording [21][22] and stimulation [23][24][25] applications.…”