Neural NoisePeripheral nerve interfaces are devices that establish electrical communication with nerves outside the brain and spinal cord, typically targeting motor and sensory nerves in the limbs. Unlike cortical approaches such as ecog or intracortical microelectrode arrays, peripheral nerve interfaces access neural signals closer to the end organs they control, offering a less invasive surgical approach while preserving functionally specific information about limb movement and sensation.
The field encompasses several device architectures spanning a range of invasiveness. Extraneural cuff electrodes wrap around a nerve trunk and record or stimulate the aggregate activity of fascicles within. Intraneural electrodes such as transverse intrafascicular multichannel electrodes (TIME) and longitudinal intrafascicular electrodes (LIFE) penetrate the epineurium to access individual fascicles, achieving higher selectivity at the cost of greater tissue disruption. Regenerative interfaces, including sieve electrodes and microchannel arrays, guide regenerating axons through electrode-bearing structures after nerve transection. Each architecture presents different trade-offs between signal resolution, long-term stability, and surgical complexity.
A defining application of peripheral nerve interfaces is bidirectional control of prosthetic limbs. Motor signals decoded from residual nerves in an amputee’s stump can drive prosthetic hand and arm movements, while sensory feedback delivered through the same or adjacent nerve electrodes can restore graded touch and proprioceptive sensations. This bidirectional capability distinguishes peripheral nerve interfaces from surface emg-based prosthetic control, which provides motor output but no sensory return. Clinical trials have demonstrated that intraneural sensory feedback improves grasp force regulation, reduces phantom limb pain, and increases the sense of embodiment of the prosthetic limb. Peripheral nerve interfaces also intersect with spinal-cord-stimulation and stimulation-and-neuromodulation in applications such as bladder control, chronic pain management, and autonomic function restoration.