title: Real-Time Control of a Neuroprosthetic Hand by Magnetoencephalographic Signals from Paralysed Patients.
abstract: Neuroprosthetic arms might potentially restore motor functions for severely paralysed patients. Invasive measurements of cortical currents using electrocorticography have been widely used for neuroprosthetic control. Moreover, magnetoencephalography (MEG) exhibits characteristic brain signals similar to those of invasively measured signals. However, it remains unclear whether non-invasively measured signals convey enough motor information to control a neuroprosthetic hand, especially for severely paralysed patients whose sensorimotor cortex might be reorganized. We tested an MEG-based neuroprosthetic system to evaluate the accuracy of using cortical currents in the sensorimotor cortex of severely paralysed patients to control a prosthetic hand. The patients attempted to grasp with or open their paralysed hand while the slow components of MEG signals (slow movement fields; SMFs) were recorded. Even without actual movements, the SMFs of all patients indicated characteristic spatiotemporal patterns similar to actual movements, and the SMFs were successfully used to control a neuroprosthetic hand in a closed-loop condition. These results demonstrate that the slow components of MEG signals carry sufficient information to classify movement types. Successful control by paralysed patients suggests the feasibility of using an MEG-based neuroprosthetic hand to predict a patient's ability to control an invasive neuroprosthesis via the same signal sources as the non-invasive method.
authors.affiliation: Osaka University Graduate School of Medicine, Department of Neurosurgery, Suita 565-0871, Japan.|ATR Computational Neuroscience Laboratories, Department of Neuroinformatics, Seika-cho 619-0288, Japan.|Nara Institute of Science and Technology, Graduate School of Information Science, Ikoma 630-0192, Japan.
authors.forename: Ryohei
authors.initials: R
authors.lastname: Fukuma
authors.affiliation: Osaka University Graduate School of Medicine, Department of Neurosurgery, Suita 565-0871, Japan.|ATR Computational Neuroscience Laboratories, Department of Neuroinformatics, Seika-cho 619-0288, Japan.|Osaka University Graduate School of Medicine, Division of Functional Diagnostic Science, Suita 565-0871, Japan.
authors.forename: Takufumi
authors.initials: T
authors.lastname: Yanagisawa
authors.affiliation: Osaka University Graduate School of Medicine, Department of Neurosurgery, Suita 565-0871, Japan.|Osaka University Graduate School of Medicine, Department of Neuromodulation and Neurosurgery, Suita 565-0871, Japan.
authors.forename: Youichi
authors.initials: Y
authors.lastname: Saitoh
authors.affiliation: Osaka University Graduate School of Medicine, Department of Neurosurgery, Suita 565-0871, Japan.|Osaka University Graduate School of Medicine, Department of Neuromodulation and Neurosurgery, Suita 565-0871, Japan.
authors.forename: Koichi
authors.initials: K
authors.lastname: Hosomi
authors.affiliation: Osaka University Graduate School of Medicine, Department of Neurosurgery, Suita 565-0871, Japan.
authors.forename: Haruhiko
authors.initials: H
authors.lastname: Kishima
authors.affiliation: Osaka University Graduate School of Medicine, Department of Neurosurgery, Suita 565-0871, Japan.|Osaka University Graduate School of Medicine, Department of Neuromodulation and Neurosurgery, Suita 565-0871, Japan.
authors.forename: Takeshi
authors.initials: T
authors.lastname: Shimizu
authors.affiliation: Osaka University Graduate School of Medicine, Department of Neurosurgery, Suita 565-0871, Japan.
authors.forename: Hisato
authors.initials: H
authors.lastname: Sugata
authors.affiliation: The University of Electro-Communications, Department of Mechanical Engineering and Intelligent Systems, Chofu 182-8585, Japan.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Yokoi
authors.affiliation: Osaka University Graduate School of Medicine, Department of Neurosurgery, Suita 565-0871, Japan.
authors.forename: Masayuki
authors.initials: M
authors.lastname: Hirata
authors.affiliation: ATR Computational Neuroscience Laboratories, Department of Neuroinformatics, Seika-cho 619-0288, Japan.|Nara Institute of Science and Technology, Graduate School of Information Science, Ikoma 630-0192, Japan.|Kyoto University, Graduate School of Informatics, Kyoto 606-8501, Japan.
authors.forename: Yukiyasu
authors.initials: Y
authors.lastname: Kamitani
authors.affiliation: Osaka University Graduate School of Medicine, Department of Neurosurgery, Suita 565-0871, Japan.
authors.forename: Toshiki
authors.initials: T
authors.lastname: Yoshimine
mesh_terms: D000328:Adult; D001186:Artificial Limbs; D062207:Brain-Computer Interfaces; D006225:Hand; D006801:Humans; D015225:Magnetoencephalography; D008297:Male; D008875:Middle Aged; D009044:Motor Cortex / Q000503:physiopathology*; D009068:Movement; D010243:Paralysis / Q000503:physiopathology; D012815:Signal Processing, Computer-Assisted