Correlation Analysis between Clinical Rating Scales and Inertial Signal Features in Parkinson’s Disease Patients

IMU) signals and clinical evaluation scales for Parkinson's disease were correlated. The study included 16 patients diagnosed with Parkinson's disease. Each subject was evaluated based on Korean Mini-Mental State Examination (KMMSE), Unified Parkinson's Disease Rating Scale (UPDRS) part 3, New Freezing of Gait Questionnaire (NFOGQ) parts 2 & 3, and Hoehn & Yahr Scale (H&Y). All subjects performed the Time Up and Go test by attaching IMU sensors to both ankles and torso. Based on the tilting angle of torso and the time of first step, the freezing and non-freezing windows were determined. Seven IMU features involving the ankle signals were calculated in the specific window. Spearman’s correlation analysis of clinical evaluation scales was performed. As a result, the freezing index and power of locomotion band (0.3-3 Hz) were recommended to determine UPDRS part 3. Also, the intensity of the locomotion band facilitated evaluation of NFOGQ part 3 regardless of freezing of gait.