Restoration of motor control and proprioceptive and cutaneous sensation in humans with prior upper-limb amputation via multiple Utah Slanted Electrode Arrays (USEAs) implanted in residual peripheral arm nerves.

The study included only two subjects, so it cannot show how most amputees would respond. The arrays were removed after 4 weeks in S3 and 5 weeks in S4, which does not allow long-term assessment of electrode recording or stimulation stability. The tested hand was a virtual computer hand, not a physical prosthetic hand used for activities of daily living. Electrode performance declined over time in one array per subject, and evoked sensations often changed location or quality between weeks. For S3, muscle signals recorded near the nerve dominated the decoding signals and limited control to 1 to 2 movements. The authors state that comparisons with control trials need to be developed, so the closed-loop result is not yet a tested efficacy outcome. Because the implant was combined with surgery, minocycline, dexamethasone, phantom-movement practice, and in S3 gabapentin, the contribution of any single component cannot be separated. S4 developed an implant-related infection, though he recovered fully.

The supplied text names Defense Advanced Research Projects Agency and the National Center for Advancing Translational Sciences as funders. It does not report author conflicts of interest or whether funders designed or wrote the study.

Do not read this as a proven way to restore usable prosthetic hand function, or attribute the result to the electrodes alone. The implant was combined with surgery, minocycline, dexamethasone, phantom-movement practice, and in S3 gabapentin, and the study cannot separate the contribution of any single component. It also used a virtual hand in two subjects for 4 weeks in S3 and 5 weeks in S4, so it is early feasibility, not a tested therapy.