经颅磁刺激下肌音与肌电特征对比及其系统辨识研究

Feature Comparison and System Identification of Mechanomyography and Electromyography under Transcranial Magnetic Stimulation

目的验证经颅磁刺激下靶向肌肉之肌音信号用于检测运动诱发电位的可行性,并对其进行系统辨识。方法 5名健康受试者参加测试实验,同步记录经颅磁刺激下受试者右侧拇短展肌的肌音与肌电信号,提取持续时间、幅值、峰峰值、区域、厚度以及潜伏期6种特征做对比分析;用传递函数和状态空间法辨识经颅磁刺激-肌音信号系统。结果肌音和肌电信号皆显示相似特征变化,并且在幅值、峰峰值和潜伏期这3个特征的变化上,肌音信号较肌电信号呈现线性变化,辨识经颅磁刺激-肌音信号系统存在4阶模型,且使用传递函数法和状态空间法辨识率均可达80%。结论经颅磁刺激下靶向肌肉的肌音信号可客观反映运动诱发电位特征、体现肌肉收缩情况,能用于医学检查运动神经信息从皮质到肌肉的传递、传导通路的整体同步性和完整性。

Objective To verify the feasibility of using mechanomyogarphy(MMG) of targeted muscles to detect motor evoked potentials(MEP) under transcranial magnetic stimulation(TMS),and to identify the transcranial magnetic stimulation-mechanomyography(TMS-MMG) system.Methods Five healthy subjects participated in the experiment.The MMG and electromyography(EMG) signal of the right hallucis brevis muscle of subjects under TMS were simultaneously recorded,then six features were extracted including duration,amplitude,peak-to-peak,area,size and silent period for comparison analysis.Transfer function and state space method were used to identify the subject’s TMS-MMG system.Results The feature changes of MMG and EMG signal were similar.MMG showed a linear change compared with EMG in amplitude,peak-to-peak and silent period.There was a fourth-order model for the identification of TMS-MMG system,and the recognition rate could reach 80% using transfer function method or state space method.Conclusion The MMG signal detected in the targeted muscles under TMS could objectively reflect the features of MEP and the muscle contraction,itc could be used for medical examination of the transmission of motor nerve information from the cortex to the muscle,and the overall synchronization and integrity of the conduction pathways.