Chaotic approach to the quantitative analysis of Parkinson's disease

A chaotic approach was applied to the quantitative analysis of Parkinson's disease (PD). Finger tapping tests were performed to analyze the degree of bradykinesia in PD patients. The voltage variation obtained from the tapping tests was sampled at 200 Hz, and the data for 15 seconds were used in the analysis. Sampled data were embedded into the phase space with various combinations of the dimension and delay time. The embedding dimension and the delay time used in this study were 16 and 13, respectively. Fractal dimension of 5 PD patients was calculated in the phase space and compared with those of 5 volunteers.