The upper limb rehabilitation robot is used for upper limb rehabilitation treatment for stroke patients, mainly to maintain and expand the patient's joint range of motion, enhance muscle strength and coordination, prevent the appearance of various symptoms such as muscle atrophy and joint spasm, and finally reconstruct limb function for return to normal life.
The existing upper limb rehabilitation robot has a single training mode, complex structure and difficult control system. Based on this situation, the team of Professor Yang Yan of Chongqing University of Technology designed a flexible upper limb rehabilitation robot pulled by ropes. This flexible upper limb rehabilitation robot also incorporates virtual reality technology to provide patients with repetitive training with specific tasks in a safe and reliable treatment environment, allowing patients to try different scenarios and different tasks, increasing the fun of rehabilitation treatment.
In the application of virtual reality technology, in order to obtain the motion coordinate information of the patient's upper limbs (wrist and elbow) in space, the researchers used the NOKOV motion capture system. Using a large amount of training data in the rehabilitation process of the patient's upper limbs, the speed that is suitable for the patient's upper limb movement is V0. The flexible upper limb rehabilitation robot performs active rehabilitation training, and measures the position change parameters of the upper limbs in the motion space in real time through the NOKOV motion capture system.
In the CPAC controller, the spatial coordinate change (V) of each frame in the motion capture system is calculated and compared with the proposed velocity (V0). When the upper limb movement speed V < V0 of the patient is measured, it means that the patient's voluntary movement ability is insufficient, and the exercise training needs to be carried out under the traction of the rehabilitation robot. The CPA control sends out a pulse signal to drive the end effector, so that the rope pulls the upper limb to move. When the upper limb movement speed V ≥ V0, it means that the patient can move voluntarily, so the end effector follows the upper limb to do active movement.
After obtaining the spatial coordinate position of the upper limb movement through the NOKOV motion capture system, the SDK plug-in is used to read the spatial coordinate position in Unity and convert it into a virtual dynamic model node coordinate system to realize virtual reality motion interaction.