Outcome measures in implantable brain-computer interface research: a systematic review

Implantable brain-computer interfaces (iBCIs) aim to restore function in patients with severe motor impairments by translating neural signals into motor outputs. As iBCI technology advances toward clinical application, assessing iBCI performance with robust and clinically relevant outcome measures becomes crucial. This systematic review analysed 77 studies, with 63.6% reporting outcome measures prospectively. Decoding outcomes were most frequently assessed (67.5%), followed by task performance (63.6%). Only 22.1% of studies reported a clinical outcome measure, often related to prosthetic limb function or activities of daily living. Successful iBCI translation and regulatory approval requires clinical outcomes developed collaboratively with individuals with motor impairments. One Sentence Summary Implantable brain-computer interface studies primarily evaluate engineering-related outcome measures over clinical outcome measures.