title: Electrocorticographic control of a prosthetic arm in paralyzed patients.
abstract: OBJECTIVE
  Paralyzed patients may benefit from restoration of movement afforded by prosthetics controlled by electrocorticography (ECoG). Although ECoG shows promising results in human volunteers, it is unclear whether ECoG signals recorded from chronically paralyzed patients provide sufficient motor information, and if they do, whether they can be applied to control a prosthetic.
  
  
  METHODS
  We recorded ECoG signals from sensorimotor cortices of 12 patients while they executed or attempted to execute 3 to 5 simple hand and elbow movements. Sensorimotor function was severely impaired in 3 patients due to peripheral nervous system lesion or amputation, moderately impaired due to central nervous system lesions sparing the cortex in 4 patients, and normal in 5 patients. Time frequency and decoding analyses were performed with the patients' ECoG signals.
  
  
  RESULTS
  In all patients, the high gamma power (80-150 Hz) of the ECoG signals during movements was clearly responsive to movement types and provided the best information for classifying different movement types. The classification performance was significantly better than chance in all patients, although differences between ECoG power modulations during different movement types were significantly less in patients with severely impaired motor function. In the impaired patients, cortical representations tended to overlap each other. Finally, using the classification method in real time, a moderately impaired patient and 3 nonparalyzed patients successfully controlled a prosthetic arm.
  
  
  CONCLUSIONS
  ECoG signals appear useful for prosthetic arm control and may provide clinically feasible motor restoration for patients with paralysis but no injury of the sensorimotor cortex.
authors: Department of Neurosurgery, Osaka University Medical School, Osaka, Japan.
authors: Takufumi
authors: T
authors: Yanagisawa
authors: Masayuki
authors: M
authors: Hirata
authors: Youichi
authors: Y
authors: Saitoh
authors: Haruhiko
authors: H
authors: Kishima
authors: Kojiro
authors: K
authors: Matsushita
authors: Tetsu
authors: T
authors: Goto
authors: Ryohei
authors: R
authors: Fukuma
authors: Hiroshi
authors: H
authors: Yokoi
authors: Yukiyasu
authors: Y
authors: Kamitani
authors: Toshiki
authors: T
authors: Yoshimine
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000671:Amputation, Surgical; D001132:Arm / Q000502:physiology; D001186:Artificial Limbs; D001931:Brain Mapping / Q000379:methods*; D004569:Electroencephalography / Q000379:methods*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010243:Paralysis / Q000503:physiopathology* / Q000628:therapy; D013003:Somatosensory Cortex / Q000502:physiology*; D055815:Young Adult