Parametric Representation of Hand Movement in Parkinson’s Disease

Abstract

Parkinson’s disease is a degenerative disorder of the central nervous system that often impairs the sufferer’s motor skills and causes specific disturbances of hand motor function. We measure the 3-dimensional hand motion trajectory of the patients, when they perform a natural manual transport task (moving an object from one place to another). The task is performed repeatedly by patients. The markers are placed on anatomical landmarks of the tracked hand and the movement of the markers is captured to 3-dimensional space by cameras.

An evaluation and a classification of the movement need proper parameters. These parameters are extracted from the 3D-trajectories of the markers. The main topic of the article is description, construction and evaluation of those parameters. The parameters can be divided into two categories: parameters derived from the motion of each marker separately and parameters describing the pose of the whole hand (relative position of the markers).

We consider parameters derived from the single marker: speed of the movement, change of the speed and change of the movement direction during the movement. Since the hand movement is repetitious an average trajectory and a variance are computed. The article describes construction of the average trajectory and the variance of the movement trajectories in 3D space. All parameters are evaluated on the test video sequences and their usage for classification of hand movement in Parkinson’s disease is considered.