ARTORG Center for Biomedical Engineering Research

Wrist Resistance Robot – measurement of wrist rigidity in Parkinson’s disease patients

Project Members:  Tobias Nef, Prabitha Urwyler, Stephan M. Gerber, Natassja Pal, David Benninger

Rigidity is one of the cardinal features of Parkinson’s disease (PD). It is defined as a change in the muscle tone when assessed by the examiner as resistance to a passive movement. In clinical practice, rigidity, together with other signs of motor impairment, is assessed with the patient based questionnaire - Unified Parkinson's Disease Rating Scale. Therefore, an objective and quantitative assessment of rigidity is required for monitoring therapeutic progress.
Top (1) and side (2) view of the lower right arm fixed via a custom-made cuff.

The Wrist Resistance Robot was developed to quantify healthy and pathological muscle tone of the wrist joint. The device encased in an aluminium body, is equipped with a DC motor, a gearbox, a belt drive, an optical encoder, custom made cuffs, handle, a rotating plate, an emergency stop button, and mechanical end stops. This enables to move the wrist joint over its full range of motion with different velocity profiles.

The goal of this study is to explore whether the device can differentiate rigidity in PD patients and healthy controls.