[Tremor Suppression on Multi-DoF Wrist Joint Based on Functional Electrical Stimulation: A Simulation Study]

Area of Science:

• Biomedical Engineering
• Rehabilitation Robotics
• Neuroscience

Background:

• Pathological tremor in the wrist joint significantly impacts daily activities.
• Existing treatments for wrist tremor have limitations in efficacy and specificity.
• Advanced control systems are needed to effectively manage multi-degree-of-freedom (DoF) joint tremors.

Purpose of the Study:

• To design and evaluate an automatic control system for suppressing pathological wrist tremor.
• To investigate the efficacy of functional electrical stimulation (FES) in tremor suppression.
• To develop a hybrid control strategy combining feedforward and optimal control.

Main Methods:

• Developed a musculoskeletal model of the wrist joint with two DoF, incorporating four key muscles.
• Utilized a second-order mechanical impedance model for wrist skeletal dynamics.
• Implemented a hybrid control strategy integrating inverse model feedforward control and Linear Quadratic Regulator (LQR) optimal control.

Main Results:

• The proposed hybrid controller demonstrated significant tremor attenuation.
• Over 94% reduction in tremor amplitude was achieved on the multi-DoF wrist joint.
• The system showed effective performance across various input conditions, including patient-specific data.

Conclusions:

• The developed automatic control system effectively suppresses pathological wrist tremor using FES.
• The hybrid control strategy offers a promising approach for managing complex joint movement disorders.
• This technology has potential applications in improving the quality of life for individuals with tremor.