基于混沌理论的嚼肌表面肌电信号分析

Largest lyapunov exponents analysis of the surface electromyograph signal of the masseter

目的用非线性理论来分析嚼肌表面肌电信号,验证咀嚼肌表面肌电信号的混沌特征。方法采集20名年轻男女个体的嚼肌在牙尖交错位(ICP)紧咬时的表面肌电信号,利用小数据量法计算肌电信号的最大李亚普诺夫(Lyapunov)指数。结果在Matlab软件平台上开发了计算最大Lyapunov指数的程序,计算出嚼肌表面肌电的最大Lyapunov指数。男性个体左右两侧嚼肌最大Lyapunov指数分别为17.882±1.7498、18.244±1.3028,女性为14.839±1.8198、14.866±1.3947,均为大于零的数值。结论嚼肌ICP紧咬时的表面肌电信号具有混沌动力学特征,提示咀嚼肌肌电信号适合采用非线性动力学的方法进行分析。

Objective To analyze the surface electromyogragh （EMG） signal of the masseter in the intercuspal position （ICP）, and testify the chaos character of the surface EMG of the muscles of mastication system. Methods 10 male and 10 female young volunteers were involved in this study, the signals of surface EMG of bilateral masseter in ICP were collected. The largest Lyapunov exponents of the EMG signals were calculated using a method from small data sets. Results Based on the platform of Matlab, a program was developed to calculate the largest Lyapunov exponents, the bilateral means of largest Lyapunov exponents of male were 17.882 ± 1.7498 and 18.244 ±1.3028, while the exponents of female were 14.839 ±1.8198 and 14.866 ±1.3947, all the data were positive values. Conclusions The signal of surface EMG of the masseter in ICP had the eharaeter of chaos, the method of nonlinear dynamics was applicable in analyzing the EMG signals of mastication system.