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1.
Unfallchirurg ; 108(7): 587-90, 2005 Jul.
Artigo em Alemão | MEDLINE | ID: mdl-16025358

RESUMO

The aim of this study was to restore the grasp function of a tetraplegic patient with a C5 spinal cord injury (SCI) by means of functional electrical stimulation (FES). Using three pairs of surface electrodes and orthotic wrist stabilisation a simple palmar grasp was realised. The FES was controlled with a switch mounted on a wheelchair or-for the first time-with an EEG-based brain-computer interface (BCI). Application of this stimulation system enabled the patient to drink for the first time after the accident from a glass without any additional help.


Assuntos
Atividades Cotidianas , Terapia por Estimulação Elétrica/métodos , Força da Mão , Quadriplegia/reabilitação , Traumatismos da Medula Espinal/reabilitação , Interface Usuário-Computador , Adulto , Vértebras Cervicais/lesões , Vértebras Cervicais/cirurgia , Ingestão de Líquidos , Humanos , Masculino , Quadriplegia/etiologia , Quadriplegia/cirurgia , Traumatismos da Medula Espinal/complicações , Traumatismos da Medula Espinal/cirurgia , Resultado do Tratamento
2.
Rehabilitation (Stuttg) ; 42(6): 371-7, 2003 Dec.
Artigo em Alemão | MEDLINE | ID: mdl-14677109

RESUMO

This paper describes a paralyzed patient diagnosed with severe infantile cerebral palsy, trained over a period of several months to use an EEG-based brain-computer interface (BCI) for verbal communication. The patient learned to "produce" two distinct EEG patterns by mental imagery and to use this skill for BCI-controlled spelling. The EEG feedback training was conducted at a clinic for Assisted Communications, supervised from a distant laboratory with the help of a telemonitoring system. As a function of training sessions significant learning progress was found, resulting in an average accuracy level of 70% correct responses for letter selection. At present, "copy spelling" can be performed with a rate of approximately one letter per minute. The proposed communication device, the "Virtual Keyboard", may improve actual levels of communication ability in completely paralyzed patients. "Telemonitoring-assisted" training facilitates clinical application in a larger number of patients.


Assuntos
Paralisia Cerebral/reabilitação , Auxiliares de Comunicação para Pessoas com Deficiência , Eletroencefalografia/instrumentação , Imaginação/fisiologia , Comunicação não Verbal/fisiologia , Processamento de Sinais Assistido por Computador/instrumentação , Interface Usuário-Computador , Potenciais de Ação/fisiologia , Biorretroalimentação Psicológica/fisiologia , Córtex Cerebral/fisiopatologia , Paralisia Cerebral/fisiopatologia , Sistemas Computacionais , Terminais de Computador , Eletromiografia/instrumentação , Eletroculografia/instrumentação , Humanos , Microcomputadores , Consulta Remota/instrumentação , Telemetria/instrumentação , Pensamento/fisiologia
3.
IEEE Trans Neural Syst Rehabil Eng ; 11(2): 177-80, 2003 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-12899267

RESUMO

The Graz-brain-computer interface (BCI) is a cue-based system using the imagery of motor action as the appropriate mental task. Relevant clinical applications of BCI-based systems for control of a virtual keyboard device and operations of a hand orthosis are reported. Additionally, it is demonstrated how information transfer rates of 17 b/min can be acquired by real time classification of oscillatory activity.


Assuntos
Esclerose Lateral Amiotrófica/reabilitação , Membros Artificiais , Auxiliares de Comunicação para Pessoas com Deficiência , Eletroencefalografia/métodos , Quadriplegia/reabilitação , Interface Usuário-Computador , Esclerose Lateral Amiotrófica/fisiopatologia , Encéfalo/fisiopatologia , Cognição , Eletroencefalografia/instrumentação , Potenciais Evocados , Mãos , Humanos , Internet , Educação de Pacientes como Assunto/métodos , Projetos Piloto , Telemedicina/métodos
4.
Neurosci Lett ; 340(2): 143-7, 2003 Apr 10.
Artigo em Inglês | MEDLINE | ID: mdl-12668257

RESUMO

Event-related beta electroencephalographic (EEG) changes were studied during wrist movements induced by functional electrical stimulation (FES) of the appropriate forearm muscles in healthy volunteers. Active and passive hand movements were investigated as control conditions. Significant EEG changes with respect to a pre-movement period were analyzed by calculating time-frequency maps of event-related (de-)synchronization (ERD/ERS) for 32 EEG channels recorded from sensorimotor and premotor areas. Immediately after the beginning of the FES movement, a prominent ERD was found, followed by a beta ERS similar to that observed after active or passive wrist movements. Both changes were maximal over the contralateral primary hand area. The main difference between active and stimulation-induced movements was that in the latter case no ERD was detectable prior to movement-onset. These findings suggest that the sensorimotor processing during FES involves some of the processes which are also involved in voluntary hand movements.


Assuntos
Ritmo beta/métodos , Potenciais Evocados/fisiologia , Movimento/fisiologia , Punho/fisiologia , Adulto , Estimulação Elétrica/métodos , Eletroencefalografia/métodos , Feminino , Antebraço/fisiologia , Humanos , Masculino , Músculo Esquelético/fisiologia
5.
Clin Neurophysiol ; 114(3): 399-409, 2003 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-12705420

RESUMO

OBJECTIVE: This case study describes how a completely paralyzed patient, diagnosed with severe cerebral palsy, was trained over a period of several months to use an electroencephalography (EEG)-based brain-computer interface (BCI) for verbal communication. METHODS: EEG feedback training was performed in the patient's home (clinic), supervised from a distant laboratory with the help of a 'telemonitoring system'. Online feedback computation was based on single-trial analysis and classification of specific band power features of the spontaneous EEG. Task-related changes in brain oscillations over the course of training steps was investigated by quantifying time-frequency maps of event-related (de-)synchronization (ERD/ERS). RESULTS: The patient learned to 'produce' two distinct EEG patterns, beta band ERD during movement imagery vs. no ERD during relaxing, and to use this for BCI-controlled spelling. Significant learning progress was found as a function of training session, resulting in an average accuracy level of 70% (correct responses) for letter selection. 'Copy spelling' was performed with a rate of approximately one letter per min. CONCLUSIONS: The proposed BCI training procedure, based on electroencephalogram (EEG) biofeedback and concomitant adaptation of feature extraction and classification, may improve actual levels of communication ability in locked-in patients. 'Telemonitoring-assisted' BCI training facilitates clinical application in a larger number of patients.


Assuntos
Paralisia Cerebral/reabilitação , Auxiliares de Comunicação para Pessoas com Deficiência , Eletroencefalografia/métodos , Interface Usuário-Computador , Adulto , Biorretroalimentação Psicológica , Barreiras de Comunicação , Humanos , Masculino , Córtex Motor/fisiologia , Paralisia/reabilitação , Índice de Gravidade de Doença , Córtex Somatossensorial/fisiologia
6.
IEEE Trans Neural Syst Rehabil Eng ; 11(4): 422-6, 2003 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-14960119

RESUMO

A "virtual keyboard" (VK) is a letter spelling device operated for example by spontaneous electroencephalogram (EEG), whereby the EEG is modulated by mental hand and leg motor imagery. We report on three able-bodied subjects, operating the VK. The ability in the use of the VK varies between 0.85 and 0.5 letters/min in error-free writing.


Assuntos
Inteligência Artificial , Córtex Cerebral/fisiologia , Cognição/fisiologia , Periféricos de Computador , Eletroencefalografia/métodos , Interface Usuário-Computador , Processamento de Texto , Algoritmos , Auxiliares de Comunicação para Pessoas com Deficiência , Potenciais Evocados/fisiologia , Humanos , Reconhecimento Automatizado de Padrão , Reprodutibilidade dos Testes , Sensibilidade e Especificidade
7.
Biomed Tech (Berl) ; 46(7-8): 186-90, 2001.
Artigo em Inglês | MEDLINE | ID: mdl-11552499

RESUMO

The aim of the present study was to investigate resonance-like frequencies of somatosensory steady-state evoked potentials (SSSEPs) during mechanical stimulation of the left and right index finger. The resonance effects were studied in a group of normal subjects at 8 frequencies between 17 Hz and 31 Hz. Band power was computed in 2 s epochs in eight 2 Hz beta bands starting from 16-18 Hz up to 30-32 Hz and referred to a baseline prior to stimulation. For each subject the band with the largest band power increase was determined on electrodes overlying the contralateral hand area. The band power maxima and therewith the "resonance-like" frequencies were found around 27 Hz.


Assuntos
Potenciais Somatossensoriais Evocados/fisiologia , Córtex Motor/fisiologia , Córtex Somatossensorial/fisiologia , Tato/fisiologia , Adolescente , Adulto , Dominância Cerebral/fisiologia , Feminino , Dedos/inervação , Humanos , Masculino , Mecanorreceptores/fisiologia , Estimulação Física , Processamento de Sinais Assistido por Computador
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