Development of unconstrained rigidity measurement system for quantitative diagnosis of Parkinson's disease

Abstract

The purpose of this study was to develop unconstrained rigidity measurement system by using small force sensors for quantitative diagnosis of Parkinson's Disease (PD). The developed measurement system was composed of two compact three-axis force sensors, a gyroscope, and surface electrodes. The force sensors were attached by sandwiching the wrist joint. The force along the Z-axis was measured to estimate elbow joint torque during flexion and extension movements. The elbow joint angle was calculated by the gyroscope attached between the two force sensors. The measurement experiments were conducted. The subjects were 25 PD patients and 20 healthy elderly volunteers. The examiner applied the measuring system to the wrist joint of the subject with the other hand and performed passive flexion and extension movements of the elbow joint. The relationships between elbow joint torque and elbow angle were calculated from the obtained data. It was shown that the slope of the relationships in the PD patients was larger than that in the healthy subjects and the bias of elbow joint torque in flexion was larger than that in extension. © 2009 Springer-Verlag.