Chronic pain, hearing loss, sleep apnea, Parkinson’s disease, epilepsy, paralysis from stroke or spinal cord injury. These are among a growing array of medical conditions that physicians are now treating with neurotechnology devices, which deliver electrical stimulus to limbs and organs. One Battelle Labs device under development even uses the brain itself to activate muscles in a paralyzed patient’s hand via an electronic “Neurobridge” sleeve worn on the forearm.