Interpretable Quantitative Description of the Digital Clock Drawing Test for Parkinson's Disease Modelling

摘要

Modelling of the fine motor motions during digital clock drawing test is performed within frameworks of the present studies to facilitate computer-aided diagnostics of the Parkinsons disease. Clock drawing test has been used to diagnose and monitor neurodegenerative diseases for a long period of time. It was one of the first tests to be digitalized. Nevertheless, its natural complexity causes many problems for the analysis of test results. Unlike simpler tests clock test drawing consists of many different elements. Therefore, it requires one to identify all the elements of the drawing and then proceed with the analysis of different elements. The presence of different elements, in turn, leads the idea to model test results on different levels. Low-level where modelling is performed on the basis of kinematic, pressure and temporal parameters describing fine motor movements. And higher level, where relative positions of elements, drawing quality and presence of the different elements are analyzed. Low-level analysis constitutes the scope of the present paper. Based on the clock drawing test results obtained for the groups of patients with diagnosed Parkinsons disease and similar, by age and size, healthy individuals. Features describing fine motor motions are constructed, whereas special attention is paid to the so-called set of motion mass parameters. Then features possessing the highest discriminative power to distinguish between Parkinsons disease patients and healthy control individuals are selected. Finally based on the selected subset of features applicability of different machine learning algorithms to support diagnostics process is evaluated.