Research on control technology of functional electrical stimulation in wrist movements based on Hammerstein model / 生物医学工程学杂志

For most of nonlinear systems, control strategy is complicated. The adaptive control methods based on the model identification can effectively improve the control precision and stability. According to the nonlinear and time-changeable characteristics of the wrist movement in the functional electrical stimulation, modeling and identification of wrist movement based on Hammerstein model were implemented. By using M sequence and invert-repeated M sequence as excitation signal, the wrist model is divided into the linear dynamic part and the nonlinear static part. The characteristics of nonlinear part being taken into consideration, an adaptive control method based on time-changeable characteristics of linear part is presented. This method simplifies the control strategy, and it is validated by the simulation experiment of FES.

Orbicularis oculi muscle activities by analyzing dog's electroneurogram / 第三军医大学学报

Objective To monitor the activities of orbicularis oculi muscle by analyzing the electroneurogram (ENG) of its innervating nerve. Methods The ENG was recorded in vivo by a cuff electrode implanted around a dog’s zygomatic branch of facial nerve. The differences between the ENG during relaxing period of the orbicularis oculi muscle and during the constricting period were analyzed to explore a way to monitor the muscle activities. Results The ENG signals indicating occurrences of eye blinking events were extracted in the study. Time-frequency analysis showed that there was no ENG difference when the orbicularis oculi muscle was in relaxing periods no mater whether it was in the nature eye-opening period or in the interval of eye blinking. The ENG of orbicularis oculi muscle in constricting period was different from the ENG in relaxing period at amplitude and frequency. Conclusion It is feasible to monitor the orbicularis oculi muscle activities by ENG analysis.