Chinese and Danish researchers have jointly developed a new wearable lower-limb robotic exoskeleton that can help stroke and spinal cord injury patients strengthen their muscles and regain the ability to walk.
The researchers from Beihang University in China and Aalborg University in Denmark designed the wearable exoskeleton with a special focus on the knee joint to ensure more fluid movement that’s comparable to the movement of the human knee. This makes it more synchronised and consistent with the patient’s natural movement.
“Our new design features a parallel knee joint to improve the bio-imitability and adaptability of the exoskeleton,” said a Professor at Beihang University’s School of Automation Science and Electrical Engineering, Weihai Chen.
This improves the wearer’s comfort because it reduces the amount of unnecessary pressure placed on the joints, and as a result makes the patient more willing to wear it for gait rehab.
“To improve the transparency of the robot, we studied the structure of the human body, and then built our model based on a biometric design of the lower limb exoskeleton,” said Prof Chen.
This design, which is part of what the researchers published in the journal Review of Scientific Instruments, is the first known use of a parallel mechanism at the knee joint to imitate skeletal muscles. The researchers believe a parallel mechanism similar to skeletal muscles could be useful for designing a bionic knee joint.
“Our design goes beyond solving the transparency problem in the knee joint – and it’s a simple structure,” said Chen.
In the future the researchers plan to expand the wearable exoskeleton’s capabilities by incorporating brain signals and virtual reality (VR) to control the exoskeleton and help make the experience more immersive.
“We plan to streamline it to be wearable, and to provide a comfortable training experience. Our team is also developing VR games to help make the training process more enjoyable,” said Chen.
“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,” concluded Chen.