The Design Of Virtual Upper Limb And Its Movement Control For Rehabilitation Training

The motor dysfunction caused by multiple reasons seriously affect the daily lives of patients,and the rehabilitation training plays an important role in the recovery of motor function.The basic research and clinical practice have confirmed that the virtual reality technology can promote physical rehabilitation through visual feedback,whose main physiological mechanism is that,the motion and memory function of mirror neurons improve the motivation of participants,then promote the short-lived motion illusions in the cerebral cortex.In recent years,people have continuously explored and improved the application of virtual reality technology in motor-rehabilitation,and used the motion scenes and limb motions provided by virtual reality to activate brain mirror neurons.To meet the needs of upper-limb rehabilitation study developed by our research group,in this thesis,the multi-joint virtual upper limb system is designed and studied,and the interactive control of virtual joint motion is realized.Firstly,this thesis analyzed the physiological structure and motor characteristics of the upper limbs.On this basis,the geometric modeling method with a solid model combined with a rod model was used to build a virtual upper limb model in the V-Realm Builder 2.0 platform and define the hierarchical model and coordinated system of the upper limb joints.Then 3ds max was used to optimize the appearance of the virtual upper limb model,so as to improve its smoothness and color fidelity.According to the characteristics of human upper limb motion,the motor control of the virtual upper limb was designed,and the rotation field was set to restrict the direction and angle of joint motion.The encoding of multiple motion modes such as the single-joint single-step motion,single-joint multi-step motion and multi-joint motion was realized.The Leap Motion somatosensory device was used to collect hand motion datas,the grip-action finger joint angle-time model was established through the analysis of the joint kinematics.Based on the aforementioned motion encoding method,the posture control matrix for hand joint motion was constructed,and equal intervals and non-equal intervals were used to compress the coding control matrix.The virtual upper limb posture model was designed and built,and the 6-axis bluetooth gesture sensor was used to detect the real motion gestural data of the human upper limb.The S-function in Simulink was used to complete the data real-time receiving and processing,and the real-time mapping relationship between the sensor attitude data and virtual upper joint motion control matrix was established.Thus the real-time human-computer interaction function of the virtual upper limb platform was realized,providing the real-time visual feedback for upper limb movement.The designed virtual upper limb platform was finally used in the research about the modulation of cortical activity by motion in our research group,so as to test its role in upper limb rehabilitation.The results showed that the platform have achieved the consistency of virtual upper limbs and human upper limb motions.The virtual upper-limb platform experiment environment provides participants with more realistic visualization of upper-limb motion.Participants had good immersion,which met the human-computer interaction needs in the research.