Research On Upper Extremity Mirror Rehabilitation Movement Control Based On Functional Electrical Stimulation

Stroke is a common refractory disease. Its high incidence, high morbidity and high mortality seriously threaten human’s life and health. Those who survive are about 75% of patients with varying degrees of loss of the ability to work, even loss of independence, which brings heavy hardens to the patients and their families. Fortunately, limb motor dysfunction caused by stroke can be relived through formal rehabilitation training with effective training method. Functional Electrical Stimulation (FES) is a rapidly developing medical technology in recent years. Its significant effect in muscle excise and nerve pathways recovery attracted the attention of many medical researchers. By combining mirror therapy and FES, an upper extremity stroke rehabilitation method is proposed and analyzed comprehensively. The main contents of this thesis include the following aspects:Firstly, to minimize the muscle fatigue induced by FES, the effect of different parameters modulation of FES on muscle fatigue is analyzed through contrast experiments. Muscle fatigue caused by FES has become a major impediment in widespread use of FES. On the other hand, reducing muscle fatigue caused by FES can make stroke rehabilitation training more effective. In order to estimate the level of muscle fatigue caused by stimulation pulse width modulation, frequency modulation and amplitude modulation respectively, a novel criterion of muscle fatigue is proposed based on surface electromyography (sEMG). By analyzing sEMG data acquired from six male subjects, the conclusion that pulse width modulation induces the least muscle fatigue is drawn.Secondly, a pulse width modulation based FES method is carried out, which can mirror the movement of the healthy side to the paralyzed side aiming to realize discrete mirror rehabilitation training. KINECT is used to capture the movement of healthy side, while FES device control paralyzed limb to complete the movement according to the healthy side. To guarantee the accuracy of movement of the paralyzed limb, a combined FES control strategy integrating Iterative Learning Control (ILC) and PD feedback is adopted. Experiments of different tracking speeds (slow, medium and fast) show that the proposed method achieved good results.Finally, mirror rehabilitation training is used to track continuous movement of healthy side in real time. Model Predictive Control (MPC) is adopted to control FES device to stimulate the muscle of the paralyzed limb to make sure that the paralyzed limb can follow the movement of healthy side with the same velocity. Simulation and experiment show that MPC based method can achieve satisfying results with acceptable precision.To sum up, by combing two kinds of rehabilitation therapies, i.e., FES and mirror therapy, a novel rehabilitation method is proposed, which can achieve discrete movement training and continuous movement training by using ILC and MPC method respectively. Simulation and experiment results show the proposed methods are simple and effective. This will play a positive role in promoting new stroke rehabilitation technology and also in enhancing stroke rehabilitation effectiveness.