| At present, a number of patients lose motor function of limbs due to spinal cord injury, stroke, and traumatic brain injury and so on. Rehabilitation training and therapy is often used to restore the motor functions for the paralyzed patients. Functional electrical stimulation (FES) is one of the important techniques well recognized by researchers and clinicians in rehabilitation field. In theory, FES uses electrical pulse of low level to stimulate the peripheral nerve of skeletal muscles in order to generate the expected movements, and it has already achieved clinical success in some applications including paraplegic walking. However, the domestic research level of FES is still low, and the FES systems are inflexible, unstable and hard to operate for the end-users at present. This work aims to develop a novel FES rehabilitation system based on bionic technology. Central pattern generator (CPG) model is studied, which is a neural circuit in the spinal cord of vertebrates. The functions of CPG are mimicked, and it is used to design the FES control system, in order to improve the effects of the FES on walking.The content of the thesis is given as follows. Firstly, the synergistic action of the muscles involved in walking movements is studied by the method of gait analysis, and the action sequence of all the relevant muscles is deeply investigated by means of both joint-angle analysis and electromyography (EMG) analysis. Secondly, model of neural oscillator, which is simplified from the CPG theory, is introduced and studied. The effects of the key parameters of CPG are analyzed, and the CPG network is designed. According to the theoretical study, a control system based on CPG is developed. Lastly, the FES experimental system and platform is constructed. The work mentioned above is verified and evaluated on the healthy subjects via real FES experimentation. The experimental results validate the feasibility of the CPG based control strategy, and guarantee the practical application of the FES lower-limb rehabilitation system. Moreover, it provides experimental support for clinical study on paralyzed patients in future. |
