1. Chulalongkorn Center of Excellence for Parkinson’s Disease & Related Disorders, Department of Medicine, Faculty of Medicine, Chulalongkorn University & King Chulalongkorn Memorial Hospital, Thai Red Cross Society, Bangkok 10330, Thailand
2. Department of Neurology, Juntendo University, Tokyo, Japan
3. Biomedical Signal Processing Laboratory, National Electronics & Computer Technology Center (NECTEC), Pathumthani, Thailand