Study On Upper Limb Muscle Synergy In End-effect Human-Machine Interaction Rehabilitation

In recent years,with the integration of robots into human life,the integration between humans and machines has become more and more intense.Rehabilitation robots that provide rehabilitation aids to patients with neurological injuries are more and more inclined to a "natural and precise" interaction model,which combines the intelligence of humans and machines to promote the integration of humans and machines.Therefore,not only the ability of the rehabilitation robot to recognize the intention of the supervisor through multi-source information capture needs to be given,but more importantly,it needs to promote the patient's muscle synergy in the process of rehabilitation exercise to meet the biomechanical properties of the human body itself.The paper focus on the "muscle synergy" that needs to be solved in the HMI(human-machine interaction),and studies the relationship between multi-channel sEMG(surface electromyography)signals and muscle synergy from muscle synergy theory.The main contents are:(1)Through the physiological structure and main muscles in different actions to determine the parameters of upper limb;establish a mathematical model of the rehabilitation system and the upper limb,which has important guiding for the training trajectory of precise rehabilitation.(2)Study on sEMG characteristics of the upper limb in HMI.It founds that the certain regularities between different muscles when the robot-assisted upper limb performs an active circular movement in two different directions of counterclockwise and a clockwise.(3)Muscle synergy analysis of the upper limb in HMI is performed.Proposed a program of muscle synergy: six target muscles are selected and the sEMG signals and trajectories are acquired by the sEMG technology and the robot during the continuous circular movement.After preprocessing,normalization and periodic segmentation,muscle synergy was extracted using nonnegative matrix factorization(NMF).The results of 7 healthy adults showed that three muscle synergies can be extracted during circular movements,which has similar synergy structures.The sEMG characteristics and muscle synergy of HMI circular movement is studied which can be used to characterize the difference of shoulder and elbow function in healthy adults based on the understanding of the upper limb.It is significance for understanding the potential control strategy of the central nervous system on the upper limb and quantifying rehabilitation assessments.