Research On The Exoskeleton System Of Wrist For Rehabilitation Training

After the injury of wrist joint,the muscle and tendon will be conglutinated and contracted due to the long-term stagnation,and the motor ability will be gradually lost.Common medical methods,such as medicine,electrotherapy and ultrasound,can alleviate the symptoms of muscle adhesion to a certain extent,but rehabilitation training must be carried out to restore the motor function.At present,the rehabilitation training process is mainly based on artificial auxiliary sports,which consumes human and material resources,and the subjective participation of patients is low,and the automation of the training process is low.This paper mainly studies a wrist rehabilitation exoskeleton robot,and studies the representation of EMG signal on human muscle state,strength and joint movement.It applies the EMG signal reflecting the patient's subjective will to the rehabilitation training of the patient,and verifies the proposed rehabilitation training by experiment.According to the physiological and kinematic characteristics of the wrist joint,and combined with some problems existing in the existing wrist exoskeleton,an open-loop adjustable wrist rehabilitation exoskeleton robot is developed,which can realize the movement of the wrist in three directions;and the stress analysis and kinematic analysis of the exoskeleton are carried out to solve the previous problems in transmission and comfort.To build a collection platform of EMG signals and study three application methods of EMG signals: to analyze the real-time state of human muscles by using EMG signals,to compare the time-domain,frequency-domain and non-linear EMG features,to extract the fatigue features of EMG signals,to identify the fatigue state of muscles by using the EMG fatigue features;to predict the joint movement angle by using the EMG signals,to analyze the method of wavelet analysis Methods to extract movement information from EMG signals,and use support vector machine to predict joint angle;use EMG signals to predict muscle strength,establish mapping relationship between EMG signals and muscle strength by polynomial fitting method,and modify the model by EMG fatigue characteristics to make the prediction more accurate.Three rehabilitation training modes are designed by using three applications ofEMG signals,which are passive rehabilitation mode based on EMG fatigue,which can adjust the movement track according to the real-time state of the patient's muscles;active rehabilitation mode based on EMG angle prediction,exoskeleton prediction of the patient's movement angle,which drives the patient to carry out rehabilitation training;and impedance rehabilitation training based on muscle force prediction Exercise mode,predict the strength of the patient's muscles for strength enhancing training.The simulation model of exoskeleton system is established,the single direction movement and three directions compound movement of exoskeleton are simulated and verified;the three rehabilitation modes are simulated and verified,the simulation results show that the three rehabilitation modes based on EMG signal can reflect the subjective intention of patients in real time,and realize the automatic and intelligent process of rehabilitation process.The exoskeleton rehabilitation system is feasible in mechanical structure and control method,and can meet the needs of patients in the whole rehabilitation training stage.