Modeling nonlinear errors in surface electromyography due to baseline noise: a new methodology.
Modeling nonlinear errors in surface electromyography due to baseline noise: a new methodology.
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DOI：
10.1016/j.jbiomech.2010.09.008
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发表时间：
2011-01-04
影响因子：
2.4
通讯作者：
Avin, Keith
中科院分区：
文献类型：
--
作者：
Law, Laura Frey;Krishnan, Chandramouli;Avin, Keith
表面肌电信号经常受到一定程度的基线噪声的污染。科学家通常在进一步分析之前从测量的EMG信号中减去基线噪声，这是基于基线噪声线性地添加到观察到的EMG信号的假设。然而，基线和EMG信号的随机性质可能使该假设无效。可替代地，“真实”EMG信号可能受到基线噪声的最小或非线性影响。当信噪比（SNR）可能最低时，该信息在低收缩强度下特别相关。因此，本模拟研究的目的是研究不同水平的基线噪声（约2 - 40%最大EMG振幅）对平均EMG爆发振幅的影响，并评估考虑信号噪声的最佳方法。模拟表明，基线噪声对最大收缩的平均EMG活动的影响最小，但随着噪声水平的增加和信号幅度的降低而非线性增加。因此，简单的基线噪声减法导致在估计低强度EMG爆发期间的平均活动时的实质性误差。相反，将EMG信号校正为基线和测量的信号幅度两者的非线性函数提供了EMG幅度的高度准确的估计。这种新的非线性误差建模方法对EMG信号处理具有潜在的影响，特别是在评估SNR可能较低的拮抗肌或小幅度收缩的共同激活时。
The surface electromyographic (EMG) signal is often contaminated by some degree of baseline noise. It is customary for scientists to subtract baseline noise from the measured EMG signal prior to further analyses based on the assumption that baseline noise adds linearly to the observed EMG signal. The stochastic nature of both the baseline and EMG signal, however, may invalidate this assumption. Alternately, “true” EMG signals may be either minimally or nonlinearly affected by baseline noise. This information is particularly relevant at low contraction intensities when signal-to-noise ratios (SNR) may be lowest. Thus, the purpose of this simulation study was to investigate the influence of varying levels of baseline noise (approximately 2 – 40 % maximum EMG amplitude) on mean EMG burst amplitude and to assess the best means to account for signal noise. The simulations indicated baseline noise had minimal effects on mean EMG activity for maximum contractions, but increased nonlinearly with increasing noise levels and decreasing signal amplitudes. Thus, the simple baseline noise subtraction resulted in substantial error when estimating mean activity during low intensity EMG bursts. Conversely, correcting EMG signal as a nonlinear function of both baseline and measured signal amplitude provided highly accurate estimates of EMG amplitude. This novel nonlinear error modeling approach has potential implications for EMG signal processing, particularly when assessing co-activation of antagonist muscles or small amplitude contractions where the SNR can be low.
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影响因子：
9.8
作者：
Dowling, JJ
通讯作者：
Dowling, JJ
影响因子：
3
作者：
Yao, Bing;Salenius, Stephen;Liu, Jing Z.
通讯作者：
Liu, Jing Z.
DOI：
10.1007/bf02474828
发表时间：
1966-01-01
期刊：
MED BIOL ENG
影响因子：
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作者：
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通讯作者：
FLASTERSTEIN, A. H.
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作者：
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通讯作者：
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影响因子：
3.2
作者：
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通讯作者：
SCOTT, RN