Patient-Specific Exercises with the Development of an End-Effector Type Upper Limb Rehabilitation Robot

Area of Science:

• Robotics
• Rehabilitation Engineering
• Biomechanics

Background:

• End-effector type upper limb rehabilitation robots (ULRRs) offer structural simplicity and precise control over joint movements.
• Compared to exoskeleton types, end-effector ULRRs excel in rehabilitating combined upper limb motions and collaborative tasks.

Purpose of the Study:

• To introduce a novel three-degree-of-freedom (DOF) end-effector type ULRR.
• To present patient-specific exercises, including passive and cooperative modes, for upper limb rehabilitation.
• To validate the robot's performance in trajectory tracking and real-time human-robot interaction.

Main Methods:

• Developed a three-DOF end-effector ULRR utilizing a four-bar mechanism and a lifting mechanism.
• Implemented patient-passive exercises based on inverse kinematics and servo drive interpolation.
• Created patient-cooperative exercises employing a simplified single-spring model for human-robot coupling, enhancing control system response speed.

Main Results:

• The mechanical design successfully achieved three DOFs.
• Patient-passive exercises demonstrated good trajectory tracking performance.
• Patient-cooperative exercises exhibited effective, flexible, and real-time interactive capabilities.

Conclusions:

• The novel end-effector ULRR is suitable for upper limb rehabilitation.
• The simplified spring model significantly improved the control system's response speed.
• Experimental results confirm the robot's efficacy in both passive and cooperative rehabilitation modes.