1. School of Biological Science and Medical Engineering, Beihang University, Beijing, China
2. Beijing Advanced Innovation Centre for Biomedical Engineering, Beihang University, Beijing, China
3. Beijing Key Laboratory of Rehabilitation Technical Aids for Old-Age Disability, National Research Center for Rehabilitation Technical Aids Beijing, China
4. Key Laboratory of Neuro-functional Information and Rehabilitation Engineering of the Ministry of Civil Affairs, Beijing, China