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bioRxiv · 10.1101/2024.04.22.590630

A flexible intracortical brain-computer interface for typing using finger movements

Shah, N. P.·Willsey, M. S.·Hahn, N.·Kamdar, F.·Avansino, D. T.·Fan, C.·Hochberg, L. R.·Willett, F. R.·Henderson, J. M.
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Abstract

Keyboard typing with finger movements is a versatile digital interface for users with diverse skills, needs, and preferences. Currently, such an interface does not exist for people with paralysis. We developed an intracortical brain-computer interface (BCI) for typing with attempted flexion/extension movements of three finger groups on the right hand, or both hands, and demonstrated its flexibility in two dominant typing paradigms. The first paradigm is "point-and-click" typing, where a BCI user selects one key at a time using continuous real-time control, allowing selection of arbitrary sequences of symbols. During cued character selection with this paradigm, a human research participant with paralysis achieved 30-40 selections per minute with nearly 90% accuracy. The second paradigm is "keystroke" typing, where the BCI user selects each character by a discrete movement without real-time feedback, often giving a faster speed for natural language sentences. With 90 cued characters per minute, decoding attempted finger movements and correcting errors using a language model resulted in more than 90% accuracy. Notably, both paradigms matched the state-of-the-art for BCI performance and enabled further flexibility by the simultaneous selection of multiple characters as well as efficient decoder estimation across paradigms. Overall, the high-performance interface is a step towards the wider accessibility of BCI technology by addressing unmet user needs for flexibility.

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Shah, N. P., Willsey, M. S., Hahn, N., Kamdar, F., Avansino, D. T., Fan, C., Hochberg, L. R., Willett, F. R., Henderson, J. M.. 2024-04-26. A flexible intracortical brain-computer interface for typing using finger movements. https://doi.org/10.1101/2024.04.22.590630

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