电极放置位置对表面肌电信号特征的影响

The Influences of Electrode Location on the sEMG Signal from the Exercise-Induced Fatigued Muscle

目的:探讨不同电极放置位置对表面肌电(sEMG)信号特征的影响。方法:健康男性大学生14名,分别采用50%、70%和90%最大随意收缩力量(MVC)强度静态屈肘运动诱发肱二头肌疲劳,同步采集肱二头肌上三个不同电极位置上的sEMG信号,采用线性和非线性信号分析方法,计算线性指标平均肌电值(AEMG)和平均功率频率(MPF)以及非线性指标C(n)和DET%。结果:电极位置只对sEMG的四个测试指标的均值产生影响,对其变化斜率无明显影响,而四个指标的变化斜率中,除AEMG变化斜率对负荷强度无明显区分度外,其余三个指标对负荷强度均有良好区分度。结论:采用MPF、C(n)和DET%变化斜率作为评价局部肌肉疲劳的客观指标,既可以忽略电极放置位置对sEMG的影响,又对不同负荷强度有良好区分度。

Objective To investigate the influences of electrode location on the sEMG signal from the fatigued muscle. Methods Fourteen male undergraduates performed three different isometric contractions （right elbow flexion） with 50%, 70% and 90% of MVC, when sEMG signals were collected from three different electrode locations on the biceps brachii. The average EMG （AEMG） and mean power frequency （MPF）, and C（n） and DET% were calculated through linear and nonlinear signal analysis. Results The electrode location affected significantly on the AEMG, but had no significant influence on the slope of sEMG. The slopes of sEMG （except the slope of AEMG） were able to differentiate the intensities of contraction. Conclusions the slopes of MPF, C（n） and DET% could be used as the objective parameters of local muscle fatigue due to the absence of the influence of electrode location.