Parkinson’s Disease Treatment as Seen from a Mechanical Point of View

Abstract

Tremor is considered as the most common faced abnormal involuntary movement disorder and the source of functional disability. Parkinson disease (PD) is a slowly progressive degenerative disorder of the central nervous system caused by the lack in the level of dopamine. Levodopa is the most effective dopaminergic medication used to manage Parkinson symptoms. However, it will be the source of the motor fluctuation after several years. An uncommon type of medication is suggested to suppress the resting tremor of PD patients. In this paper, a vibration absorber is used as a mechanical treatment and designed to reduce critical angular displacement amplitude at the resonance frequency. Human hand is modeled dynamically at the musculoskeletal level to reflect Parkinsonism. Motion is considered due to shoulder, elbow, Biceps brachii and wrist muscles activation. Absorber's geometry, materials properties and parameters are well chosen to satisfy the tuning condition. The solution to the equation of motion for the hand is shown in the frequency and time domains to check the performance of the absorber in reducing the flexion angular motion at the wrist joint. Results show that the absorber was very effective over a good frequency bandwidth. It was able to reduce 93% of tremors amplitude at the wrist joint in the frequency domain. This type of absorber has low cost, can operate without power requirements, and has a simple design. Since its effectiveness was proved when tested numerically, it is recommended to proceed to the manufacturing process and the experimental study.