Trajectory Control-An Effective Strategy for Controlling Multi-DOF Upper Limb Prosthetic Devices

Area of Science:

• Biomedical Engineering
• Rehabilitation Robotics
• Human-Machine Interfaces

Background:

• Current upper-limb prosthetics face challenges in intuitive control due to limited user inputs.
• Sequential control, operating one joint at a time, is common but inefficient.
• Simultaneous control is emerging but remains complex for users.

Purpose of the Study:

• To introduce and evaluate a novel control strategy called trajectory control for multi-joint upper-limb prostheses.
• To assess the efficacy of trajectory control compared to sequential and simultaneous control methods.
• To investigate user experience and movement naturalness with the proposed control approach.

Main Methods:

• Developed trajectory control, coupling multiple degrees of freedom (DOFs) into predefined, user-selectable motion trajectories.
• Designed trajectories based on human motion studies of daily activities.
• Conducted a human subjects study in a virtual environment to evaluate control strategies.

Main Results:

• Participants using trajectory control completed tasks faster, especially with more complex (higher DOF) prosthetic systems.
• Trajectory control demonstrated comparable body compensation to sequential and simultaneous control.
• Users reported trajectory control as more intuitive and observed more natural limb movements.

Conclusions:

• Trajectory control enhances prosthetic usability by simplifying the control of multi-joint upper-limb devices.
• This approach offers a promising alternative for improving functional outcomes in amputees using advanced prosthetics.
• Future research should explore real-world applications and further refine trajectory-based control systems.