Trends in neuroprosthetic technologies to restore sensations

The loss of sensory function significantly reduces the ability to perform daily activities and lowers quality of life. Accordingly, the artificial replacement or support of impaired sensory function has become one of the main objectives of neural engineering and neuroprosthetics. This review systematically organizes auditory, visual, and somatosensory restoration technologies by target organ-from peripheral sensory organs to the central nervous system-and provides a comprehensive overview of the achievements and limitations of each approach. Auditory restoration includes cochlear, brainstem, and auditory cortex approaches; visual restoration includes retinal, optic nerve, and visual cortex approaches; and somatosensory restoration includes somatosensory cortex and peripheral nerve approaches. Although neuroprosthetics-based sensory restoration technologies have achieved considerable progress, the sensations currently restored remain far from natural perception. This review discusses future directions to address these limitations, focusing on higher-density electrodes, device and system optimization, decoding-based biomimetic stimulation, and personalized stimulation strategies. Ultimately, these advances may enable more natural sensation and improve the quality of life of patients with sensory impairments.