Synergy Based Functional Electrical Stimulation Strategy On Stroke Rehabilitation

Stroke has a high rate of disability,more than 60% stroke patients are suffering from different levels of motor function disorder.Neuromotor rehabilitation has become a serious problem.Functional electrical stimulation(FES)has been proved promising for stroke rehabilitation,but it remains challenging to find a multi-muscle FES strategy.Muscle synergy is an efficient strategy the central nervous system uses to control human activities.This paper discusses the application of synergy based FES strategy in stroke rehabilitation.First,I proved that muscle synergy can be used in motor control through simulation.Virtual-Arm model were used,covering the elbow joint,the short head of biceps brachii and the long head of triceps brachii.Synergy based signal was used as the input signal to simulate the planar flexion and extension movement of the elbow.The angle and the angular velocity of elbow joint was analyzed.We successfully got different results as expected by adjusting the synergy patterns,which indicates that muscle synergy can be used in motor control.Then,real time FES on/off experiments were operated in order to test the feasibility of applying synergy based multi-muscle FES strategy to stroke rehabilitation.Horizontal reaching movement towards two different ways were chosen to be the tasks.Kinematics and EMGs of 2 joints and 7 muscles were recorded and analyzed.3 stroke patients participated in real time on-off test.They were asked to finish the tasks with and without FES.Results show that the maximum velocity gets higher while they receiving FES intervention.At last,I proved that synergy based FES strategy is helpful in stroke rehabilitation by clinical intervention test.7 patients with post-stroke hemiparesis were recruited for clinical intervention test.5 of them received a 5-day FES intervention,while 1 received the same intervention without FES.The last patient received both two interventions.All subjects were taking the normal treatment from hospital.Kinematics,electromyography(EMG),and Fugl-Meyer scores of patients were measured both before and after intervention.All patients showed increased Fugl-Meyer scores and peak movement velocity after 5 days of FES intervention.No comparable improvements were observed after sham interventions.Particularly,a self-comparison in the patient received both sham and FES interventions highlighted the effectiveness of FES.This indicates that it is feasible to accelerate the recovery of stroke patients using synergy based FES strategy.This protocol showed obvious effectiveness after a short period of intervention.This research provides a new quick and valid way for stroke rehabilitation.Further research may eventually change the structure of stroke rehabilitation at some level.