In good news for stroke and spinal cord injury patients, researchers have designed a lower-limb robot exoskeleton -- a wearable robot that features natural knee movement to help patients regain the ability to walk or help strengthen their muscles.Researchers from Beihang University in China and Aalborg University in Denmark developed the wearable robot to greatly improve patients' comfort and willingness to wear it for gait rehabilitation.The team's approach focused on the knee joint, one of the most complex mechanical systems within the human body and a critical player during gait.The knee joint's motion is actuated by several skeletal muscles along its articular surfaces, and its center of rotation moves."Our new design features a parallel knee joint to improve the bio-imitability and adaptability of the exoskeleton," explained Weihai Chen, professor at Beihang University.
Movement transparency is critical when wearing a robot for gait rehab.When wearing the exoskeleton, its movement should be synchronised and consistent with a patient's natural movement.For this, the team focused on bionic mechanical design."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.This design is the first known use of a parallel mechanism at the knee joint to imitate skeletal muscles.As far as its applications, the exoskeleton's main role will be to help stroke or spinal cord injury patients with their rehab."We plan to streamline it to be wearable and to provide a comfortable training experience," Chen noted in the journal Review of Scientific Instruments.The team is also developing virtual reality games to help make the training process more enjoyable.The next step for the team is to collaborate with hospitals, because testing the robot out with patients can provide critical feedback from patients and doctors.