Research On Evaluation Of Human Body Balance Ability Based On The Feature Of Brain Function Network

Balance ability reflects the overall coordination of human sensation,nerve control,muscle and bone.It relies on the information input of three senses,namely vision,proprioception and vestibular perception,which is processed and integrated by the central nervous system.Regulation is carried out through the ankle,hip and knee strategies.Because of the senility and lesion,the balance ability of human will decline In the diagnosis and treatment of balance disorder,it is necessary to accurately evaluate balance ability for determining the level of balance disorder and developing appropriate rehabilitation methods.The current methods of balance assessment were based on the external manifestation of human body balance,but the internal neurophysiological regulation mechanism was seldom considered.Therefore,based on the traditional center of pressure signal study,this paper analyzed the EEG and sEMG signals related to balance from cortico-muscular coherence,constructed the balance brain function network,studied the regulation rules of the central system,and evaluated the balance ability of human body more comprehensively.The main research contents and innovations of this paper are as follows:?1?Based on the comparative analysis of balance ability,four experimental paradigms of human static balance including blocking proprioception and vision were designed.By blocking the input of balanced sensation,signals of center of pressure,equal-related electrical signals of lower limb muscles and cerebral cortex were collected.The four experimental paradigms are standing with eyes open on the balance force platform,standing with eyes closed on the balance force platform,standing with eyes open on the balance force platform+spongy cushion,and standing with eyes closed on the balance force platform+spongy cushion.At the same time,the standing posture of the subjects and the requirements of the experiment were specified.?2?Based on coordinated response analysis of the central nervous system in the absence of balanced sensation,a new brain functional network feature of balance problem was proposed.First,the characteristic indexes of the center of pressure signals under the four paradigms were calculated to judge the balance state of the four experimental paradigms.Second,from cortico-muscular coherence analysis,the phenomenon that the brain-muscle coherence is more significant in the ???band was found.With the change of experimental paradigm,the coherence of the y band presents a certain regularity.Therefore,we extracted from the ? band which is more apparent,and built the balance brain function network.We found the local activity of the occipital lobe and the central regions are reduced when sensory is blocked,while the network complexity of the frontal area which involved in integration of the central nervous system increases.It indicates that the frontal lobe is involved in the balance regulation when sensation is blocked,so we inferred that the frontal lobe regulation is an organic component of the balance ability,and the enhancement of frontal lobe regulation is an emergency response to the weakening of balance ability.?3?The ratio of the clustering coefficient in occipital lobe and central brain region to frontal lobe was defined as the balance sensory regulation coefficient D₁,D₂.The balance response activation level during sensory blockade was added to the assessment of balance ability,as the feature of brain network related to balance sensory input and integration.The clustering coefficient CC of global brain network was taken as the overall feature of balance coordination.The above features were combined to form the feature vector[CC,D₁,D₂]of brain function network about balance problem,which reflects the sensory input and integration during the human balance regulation.It comprehensively reflects the balance ability of human body from the balanced sensory input and integration perspectives.In this paper,from the perspective of balance neurophysiological regulation,we extracted feature vectors[CC,D₁,D₂]of brain functional network about balance problem from the ? band.Support vector machines were used to evaluate the balance ability of human body.This method fully considered the balance mechanism of cerebral cortex,extracted effective features and evaluated the balance ability.The balance assessment method of this paper is superior to the other feature groups of brain function network from the balance assessment results of the young group and the old group,and achieves a better classification accuracy as the traditional plantar pressure signal assessment method.It shows that it is feasible to evaluate the balance ability of human body from the perspective of central nervous control.The method of this paper only needs to collect EEG signals,which is less limited to the site and is a strong convenience.Meanwhile,it uses the brain function network to conduct in-depth research on the balance physiological activities,to analyze the regulation rules of the central system and extract new feature of the balance brain network,which is an effective new idea for the balance assessment.