First-in-Human Trial

The first study in which a device is implanted in or applied to living people rather than animals or cadavers, marking the transition from preclinical to clinical evidence. For implanted BCIs these are typically small (single digits to low tens of participants) open-label early feasibility studies whose primary aim is safety and basic feasibility — can the device be implanted and explanted safely, does it record usable signals, can a participant achieve any control — rather than statistically powered efficacy.

Because the cohort is tiny and highly selected, first-in-human results are proof-of-principle, not evidence of population benefit; striking performance in a handful of exceptional participants over months may not generalize. These studies also carry the heaviest uncertainty about long-term risk, since chronic effects are by definition unobserved at enrollment and only accrue with follow-up.