IEEE Trans Neural Syst Rehabil Eng. 2016 Oct;24(10):1081-1088. doi: 10.1109/TNSRE.2016.2521612. Epub 2016 Jan 27.
Parameters derived from the goniometer measures in the Pendulum test are insufficient in describing the function of abnormal muscle activity in the spasticity. To explore a quantitative evaluation of muscle activation-movement interaction, we propose a novel index based on phase amplitude coupling (PAC) analysis with the consideration of the relations between movement and surface electromyography (SEMG) activity among 22 hemiplegic stroke patients. To take off trend and noise, we use the empirical mode decomposition (EMD) to obtain intrinsic mode functions (IMFs) of the angular velocity due to its superior decomposing ability in nonlinear oscillations. Shannon entropy based on angular velocity (phase)-envelope of EMG (amplitude) distribution was calculated to demonstrate characteristics of the coupling between SEMG activity and joint movement. We also compare our results with those from traditional methods such as the normalized relaxation index derived from the Pendulum test and the mean root mean square (RMS) of the SEMG signals in the study. Our results show effective discrimination ability between spastic and nonaffected limbs using our method . This study indicates the feasibility of using the novel indices based on the PAC in evaluation the spasticity among the hemiplegic stroke patients with less than three swinging cycles.
从摆锤试验的量角器测量中得出的参数在描述痉挛状态下异常肌肉活动的功能方面是不够的。为了探索肌肉活动-运动相互作用的定量评估，我们提出了一种新的基于相位振幅耦合（PAC）分析的指标，考虑了运动和表面肌电图（SEMG）活动之间的关系，该指标应用于 22 例偏瘫脑卒中患者。为了去除趋势和噪声，我们使用经验模态分解（EMD）来获得角速度的固有模态函数（IMF），因为它在非线性振荡中具有优越的分解能力。基于角速度（相位）-EMG（幅度）分布包络的香农熵被计算出来，以展示 SEMG 活动与关节运动之间的耦合特征。我们还将我们的结果与传统方法（如摆锤试验得出的归一化弛豫指数和 SEMG 信号的均方根（RMS）的平均值）进行了比较。我们的结果表明，使用我们的方法可以有效地区分痉挛肢体和非痉挛肢体。这项研究表明，基于 PAC 的新指标在评估偏瘫脑卒中患者少于三个摆动周期的痉挛状态方面具有可行性。
