Recent work has shown the potential for robotics to be implemented in the rehabilitation of patients suffering stroke and spinal cord injury. Researchers from Beihang University in China and Aalborg University in Denmark have developed a robotic exoskeleton that can help in training to advance gait rehabilitation and strengthen muscles.

The lower-limb wearable robot exoskeleton features a natural knee movement for optimum transparency and improving patients comfort and willingness to wear for gait rehabilitation. The exoskeleton is specifically designed to strengthen the muscles for walking, training of paralyzed patients and assistance in performing daily activates.

"Our new design features a parallel knee joint to improve the bio-imitability and adaptability of the exoskeleton," reported Weihai Chen, a professor at Beijing's Beihang University's School of Automation Science and Electrical Engineering, in Review of Scientific Instruments.

The exoskeleton incorporates a 1-degree of freedom (DOF) hip joint piece and a 2-DOF knee joint component on the sagittal plane, as well as a planar 2-DOF parallel mechanism to copy the rotation and sliding movement of an actual human knee.  In future designs researchers hope to also incorporate the control of the exoskeleton using the patient’s electromyography signal, using their own electrical signals of the skeletal muscles to engage their own training.

"To improve the transparency of the robot, we studied the structure of the human body, then built our model based on a biometric design of the lower limb exoskeleton," Chen said. "We can obtain the movement intention from a patient's electroencephalogram (EEG)—brain signals—and use it to directly control the exoskeleton. These improvements should enable easy control and make the exoskeleton act as part of the human body."