Multibody Analysis and Control of a Full-Wrist Exoskeleton for Tremor Alleviation

Area of Science:

• Biomedical Engineering
• Robotics
• Human-Machine Interaction

Background:

• Pathological tremor significantly impairs wrist function and object manipulation.
• Existing exoskeletons often address limited wrist motion, neglecting coupled movements.

Purpose of the Study:

• To introduce and analyze the feasibility of a novel tremor alleviating wrist exoskeleton (TAWE).
• To develop a system capable of monitoring and suppressing tremors while augmenting wrist power.
• To account for coupled 3D wrist motions, including flexion/extension (FE) and radial/ulnar deviation (RUD).

Main Methods:

• Analytical multibody modeling of the forearm-TAWE system.
• Development of a six degrees-of-freedom (DOF) rigid linkage exoskeleton.
• Implementation of nonlinear regressions for controller design parameter identification.
• Numerical validation using V-REP simulations.

Main Results:

• The analytical model provides insights into control conditions achievable through design parameter tuning.
• Nonlinear regressions successfully identified crucial information for controller design.
• V-REP simulations confirmed the analytical model's accuracy and the TAWE's reliable performance.
• The TAWE demonstrated effectiveness in tremor suppression and movement assistance for coupled FE and RUD motions.

Conclusions:

• The proposed TAWE design is feasible for mitigating pathological wrist tremor.
• The developed analytical framework supports the design and control of multi-DOF wrist exoskeletons.
• TAWE shows promise for restoring dexterity and improving object manipulation for individuals with tremor.