The only way to get approval to experiment on human subjects is by specifically intending the device to treat a condition, and then only testing on individuals with that condition. You can't just take volunteers off the street and start testing chemotherapy drugs on them for example - this is to avoid exploiting the poor and indigent as human lab rats.
They need to thread the needle of a condition so advanced that a brain link device would potentially restore a basic essential of life but also not so advanced that the patient can no longer give consent.
