基于传递熵与广义偏定向相干性的肌间耦合分析

Intermuscular Coupling Analysis Based on Transfer Entropy and Generalized Partial Directed Coherence

目的将传递熵(transfer entropy,TE)与广义偏定向相干性(generalized partial directed coherence,gPDC)引入肌间耦合分析中,探讨运动中相关肌肉在时频域的肌间耦合特性。方法采集8名健康志愿者在屈肘状态下的屈腕运动时的表面肌电信号(sEMG),时域上进行TE分析,频域上进行gPDC分析,并且与传统的相干性方法进行比较。结果上肢运动过程中,时频域上BB→BR的耦合程度均强于BB→TB,BB→BR的耦合程度强于BR→BB;频域上肌间耦合突出表现在beta与gamma频段,BB→BR与BB→TB的gPDC曲线在beta与gamma频段出现显著波峰,比相干性更准确地揭示肌间耦合关系。结论中枢神经系统对运动过程中的协同肌与拮抗肌采取了不同的调节支配方式,控制协同肌以更加同步的方式活动,且肌间耦合包含了丰富的方向信息。

Objective The transfer entropy（TE） and generalized partial directed coherence（gPDC） were introduced into the intermuscular coupling analysis to investigate the intermuscular bidirectional functional coupling characteristics.Methods Eight healthy subjects were asked to perform the wrist flexion during upper elbow flexion,and s EMG data was collected from musculi brachialis（BR）,musculus biceps brachii（BB） and musculus triceps brachii（TB）.TE was used in the time domain analysis,and gPDC was computed in the frequency domain.Then the results were compared with that of the traditional coherence analysis approach.Results The coupling degree of BB→BR was stronger than BB→TB in the time-frequency domain,and the coupling degree of BB→BR was also stronger than BR→BB during the upper limb movement.Additionally,intermuscular coupling prominently existed in the beta and gamma bands,and the gPDC curves of BB→BR and BB→TB showed significant peaks in the beta and gamma bands,which could detect the intermuscular coupling relationship with better accuracy than the coherence analysis algorithm.Conclusion The central nervous system takes a different mode of regulation and control over synergistic and antagonistic muscles,and the congenerous muscles are coordinated by the central nervous system in a more synchronous way during the upper limb movement.Furthermore,the intermuscular coupling contains rich direction information.