Contactless evaluation of rigidity in Parkinson’s disease by machine vision and machine learning

To the Editor:Parkinson’s disease(PD)is one of the most common neurodegenerative movement disorders.[1]Its cardinal symptoms include bradykinesia,tremor,and rigidity.[2]The severity of PD-related motor symptoms is usually semiquantitatively evaluated by the Movement Disorder Society-sponsored revision of the Unified Parkinson’s Disease Rating Scale(MDS-UPDRS)[3]part three(MDS-UPDRS III).A series of machine perception and machine learning technologies have been applied to assist the manual rating of motor symptoms.[4,5]Machine vision,which does not require physical contact between the examiner and the patient.