Research On Brain-controlled Functional Electrical Stimulation

Physical injuries or nervous system trauma will result in different levels of motor function loss,which brings great pain to those patients.Functional Electrical Stimulation(FES)is an effective rehabilitation technique that utilizes mild electrical currents to activate paralyzed nerves and muscle,and has become a new approach for neuromuscular function recovery and reconstruction.Brain-Computer Interface(BCI)can restore the lost motor function through directly deciphering the motor intents from brain,bypassing damaged spinal cord or peripheral nerves,and translating them into commands for artificial auxiliary equipment to complete alternative movement.Brain-controlled FES provides an alternative way for online stimulus strategies adjusting by the users.However,motor function recovery and reconstruction is a long-term process,and understanding of the neuromodulation will help improve the effect of such process.Research on neuromodulation requires long-term animal studies before carrying out clinically.The traditional surface muscle electrical stimulator uses electrical stimulation muscle surface to produce limb movement.However,in such circumstance,the direction of the current and actual neural signal transmission is opposite,thus the stimulated muscle will fatigue quickly,being unfavorable for long-term experiments.The alternative FES that implants and battery connected through a wire,although the direction of the stimulus current and actual neural electrical signals is same,but the friction between wire and organization may be the cause of the discomfort of animals even infection,so that it is also unfavorable for long-term experiments;a fully implantable electrical stimulator with battery can solve the above problem,but the volume of the battery need to be small enough,can carry less electricity,need surgery to replace a new battery again,even the rechargeable battery,because of the charging efficiency,it is also unfavorable for long-term experiments.In view of the above problem,this paper developed a fully implantable stimulator with wireless power and data transmission for long-term experiments,providing the technical support to the research of neuromodulation.At the same time,in this paper,the experiment of BCI,due to involve the training of the primate,electrode implant and data acquisition,etc.,is a long-term animal research,each experiment takes about half a year time,so we must provide a fully implantable stimulator that can be used for long-term experiments.There are also economic principles of cellular neural mechanisms.First,at the stage of movement planning,a large number of neuronal cells do not participate in the coding of motor-related factors.During the stage of movement execution,motor-independent neurons are transformed into motor-related neurons in large numbers.Secondly,in the motion planning stage,The number of neurons associated with the orientation of the target is significantly increased in the stage of the movement,and finally,the use of the signal of the planning phase to predict how to execute movement,the case of randomly perturbed task obtain lower accuracy.The above results show that the motor cortex in the dynamic changes in the functional properties of neurons,and for the determination of the situation,will focus on the deployment of a large number of neurons into the required functional neurons,and in the uncertain circumstances,the cerebral cortex is more "economy" to wait.This dissertation described the process of building the brain-controlled FES platform,and the main achievements and innovations are:1)To explore the neural mechanism of neural mechanisms during the stage of reaching and grasping in three-dimensional space,how to change of neuron function in the motor planning and execution phase by using two-way ANOVA,and to elucidate the existence of a neuronal discharge activity associated with dynamic allocation mechanism;2)propose a adaptive motor control framework for neuron adaptive control,which is suitable for the completion of similar motion tasks,and has important guiding significance for the design of high performance brain computer interface;3)developed a fully implantable stimulator with wireless energy and power transmission,all indices meet the requirements of long-term animal's experiments,and the effectiveness and biocompatibility of the stimulator were verified by animal experiments..