Techniques of measurement for Parkinson's tremor highlighting advantages of embedded IMU over EMG

For Parkinson's disease (PD) detection at its best, early diagnosis of the disorder is the key criteria to be focused [5]. Tremors are one of the primary characteristics of PD [11][13]. The paper presents some of the effective biomechanical techniques that can aid in measuring PD tremors with a high grade of accuracy and sensitivity. The paper describes the application of salient tracking tools like magnetic trackers and optical markers, electrical diagnostic practices like Electromyogram (EMG) and the use of Microelectromechanical systems (MEMS) based inertial sensor modules(a combination of 3 axes accelerometer + 3 axes gyroscope) to record movement. The IMU and electrodes were suitably mounted on the hands of subjects who were made to perform certain pre-defined actions to record the wrist movement and electrical activity simultaneously. The ability of a subject to precisely follow a pre-defined task's motion trajectory is a crucial indicator of tremor. In this paper we study two techniques of trajectory measurement, in terms of the accuracy of measurement of the slightest deviations from a prescribed trajectory. It is shown that an IMU based motion tracking is more accurate than that tracked by EMG sensors.