A Study Exploring Motor And Sensory Function Restoring Based On Invasive Neural Interface

Limb disability damages the motor and sensory function of patients and reduces their life quality,while bringing a great of burden to the family and society.However,the effect of traditional drug treatment and rehabilitation aids treatment is limited.With the development of neuroscience,manufacturing science and information science,the emerging neural interface technology has shown great potential in restoring motor and sensory function for patients with limb disability.By implanting neural electrodes into the nervous system,implanted neural interface provides a "window" to connect the nervous system with the outer equipment and make the patient control the outer equipment directly with the mind for restoring motor functions,while the neural interface can provide sensory feedback by using different modes of microstimulations for restoring sensory functions.Restoring the motor and sensory function by implanted neural interface has been in the spotlight for years.The implanted neural interface can be divided into the implanted brain machine interface and implanted peripheral neural interface.The implanted brain machine interface has a stronger ability to repair motor and sensory functions but is very invasive,while the application of implanted peripheral neural interface is narrower but is less invasive and has a stronger potential for clinical application.In this dissertation,the two kinds of neural interface have been constructed and monkey behavioral experimental paradigms have been designed.On the same time,this dissertation investigated the activity of cortical and peripheral neural signals which devote to upper limb motor control and sensory feedback.This dissertation also studied the possible methods for decoding motor intentions and providing sensory feedback based on brain machine interface and peripheral neural interface.Firstly,this dissertation constructed a motor brain machine interface platform and designed a unique monkey upper limb reach-to-grasp experimental paradigm.By implanting neural electrodes into motor and sensory related brain areas,high quality neural signals reflecting the activity features of motor and sensory neurons were acquired.Neural signals recorded from different areas were combined to do the movement decoding and high decoding accuracy has been achieved.A sensory brain machine interface platform was constructed based on the motor brain machine interface platform,a unique monkey upper limb sensory experimental paradigm was designed and the working mechanism of sensory neural activities was studied,then a method for restoring sensory function by intracortical microstimulation has been proposed.In designing new neural decoding method,the motion intention recognition based on the field potential signal is carried out for the limitation of the recorded action potential signal.Different from the previous researches,this dissertation used the high frequency local field potential signal to do the motion intention decoding.A new wavelet packet transform method was used to extract features to do the decoding.The result indicated that high decoding accuracy can be achieved,while better and more robust decoding performance can be achieved by LFPs from multi-cortex than single cortex.Then,for the problem of decoder calibration in implanted brain machine interface,the transfer learning theory was brought into the implanted brain machine interface decoder calibration for the first time and a new decoder calibration method based on transfer learning has been proposed.This method can achieve good performance by only using ultra small current sample set and reduce the demand for current sample set in decoder calibration,may facilitate the application of intracortical brain-machine interfaces in clinical practice.For the shortcomings of the implanted brain machine interface,a study of the implanted peripheral neural interface is carried out.A long-term implanted peripheral neural interface based on monkey has been constructed for the first time in China,which realized the simultaneous acquisition of cortical and peripheral neural signals.Based on the peripheral neural interface,the grasping movement of the monkey was successfully reconstructed by combining the interfascicular peripheral electrode and intrafascicular electrode to do the electrical stimulation.Moreover,a sensory reconstruction experiment based on peripheral nerve stimulation has been designed,the monkey has been trained to do the tasks successfully which demonstrated that the monkey can express the sensation through movement and monkey can be used as the subject to do the sensory reconstruction experiment.