1. Division of Regenerative Medicine for Musculoskeletal System, Faculty of Medicine, University of Tsukuba, Tsukuba, Japan
2. Department of Orthopaedic Surgery, Faculty of Medicine, University of Tsukuba, Tsukuba, Japan
3. Center for Innovating Medicine and Engineering (CIME), University of Tsukuba Hospital, Tsukuba, Japan
4. Department of Rehabilitation Medicine, University of Tsukuba Hospital, Tsukuba, Japan
5. Department of Neurosurgery, Faculty of Medicine, University of Tsukuba, Tsukuba, Japan
6. Faculty of Systems and Information Engineering, University of Tsukuba, Tsukuba, Japan