Position and torque control via rehabilitation robot and functional electrical stimulation

Area of Science:

• Neurorehabilitation
• Biomedical Engineering
• Robotics

Background:

• Neurological conditions impair motor function, necessitating advanced rehabilitation.
• Functional Electrical Stimulation (FES) and robotic assistance are key therapeutic modalities.
• Combining FES and robotics offers synergistic potential for enhanced recovery.

Purpose of the Study:

• To develop and implement a hybrid FES-robotics system for biceps brachii rehabilitation.
• To create controllers ensuring stability and precision in combined therapy.
• To evaluate the system's efficacy in position and torque tracking.

Main Methods:

• Development of two distinct control strategies for integrated FES and robotic actuation.
• Application of Lyapunov stability analysis to prove global exponential stability for position and torque control.
• Experimental validation using an able-bodied participant to assess system performance.

Main Results:

• The developed controllers achieved stable position and torque tracking.
• Experimental results showed an average Root Mean Square (RMS) error of 5.8 degrees for position tracking.
• An average RMS error of 0.40 Newton-meters was recorded for torque tracking.

Conclusions:

• The integrated FES and robotic system effectively controls forearm movement and muscle exertion.
• The control strategies ensure robust performance, validated by theoretical analysis and experiments.
• This combined approach shows promise for advanced neurorehabilitation of the upper limb.