Title:  Real-time Closed-loop Tremor Modulation using Peripheral-nerve Stimulation

Committee: 

Dr. DeWeerth, Advisor

Dr. Inan, Co-Advisor     

Dr. Butera, Chair

Dr. Grover

Abstract: The research objective of this proposal is to modulate/suppress tremor movement by optimizing the parameters of electrical stimulations on peripheral nerves using a custom-designed real-time closed-loop system. To develop a non-invasive treatment technique for patients with upper limb treatment-resistant tremor, we have designed a wireless wearable stimulation system that utilizes tremor movement using a three-axis accelerometer to modulate tremor movement with a real-time closed-loop algorithm. We analyze tremor movements by changing the stimulation parameters (i.e., amplitude, frequency, duty cycle, phase, stimulation sites, and time spacing between the pulse trains) to find an open-loop response for the tremor movement by various stimulation parameters. The real-time tremor analysis provides the phase information of each tremor cycle, and we investigate the effects of phase-locked stimulation using an accelerometer and electromyography. The standardized tasks based on the Fitts' law have been used for assessing the performance of arm movement with tremor by controlling a three-dimensional gyration mouse on a computer. The quantitative tremor assessment method can be used for the evaluation of the efficacy of electrical stimulation for patients with upper limb tremor. The real-time closed-loop tremor mouldation system determines the most effective stimulation parameter sets, and we evaluate the system using a quantitative assessment that verifies the efficacy of stimulation.