A Study Of Tremor In Parkinsons Disease Using Signals From Wrist-Worn Inertial Measurement Sensors

Parkinson’s Disease (PD) is the second most common neurodegenerative disorder with tremor being its primary motor symptom. Although the MS-UPDRS is the current clinical method for evaluating the severity of tremors in PD, it has several drawbacks resulting from the subjective, visual-based examination, and the ordinal scale used to rate the tremors. Since, the MS-UPDRS is agnostic to the etiology of the tremor, age related increase in naturally occurring physiological tremors may confound the precise rating of PD tremors. However, replacing the judgment of the neurologist in determining the holistic progression of PD and treatment protocol is neither feasible nor advisable. This research used lightweight, wearable, non-invasive sensors to detect, analyze, and differentiate changes in wrist kinematics due to physiological and PD tremors. Findings reveal key differences and similarities in composition between these different types of tremors. Dominant frequency analysis using a data-based approach shows interesting parallels with the frequency range found in literature for these tremors. Finally, using features of tremor signal obtained from the sensors, a novel Tremor Severity Score rating scale was created that shows greater sensitivity in differentiating rest and postural tremors as well as medication effects on these tremors in PD patients compared to the MS-UPDRS. This study offers a simple method for objectively evaluating Parkinsonian tremors, identifying kinematic distinctions between rest and postural tremors, analyzing the effect of anti-parkinsonian medication on these tremors, and sensitively scoring tremors. These objective methods could be valuable for early diagnosis and distinguishing between different tremor causes in both clinical and telehealth settings, as well as for investigating the effects of various treatment methods on tremors.