基于表面肌电信号的小儿脑瘫步态活动段检测研究

Detection study of walking segments of children with cerebral-palsy based on surface electromyographic signals

本文采用小儿脑瘫患者步行时下肢的表面肌电信号(sEMG),对其步态运动的特征参数进行分析,拟达到对小儿脑瘫患者的临床严重程度进行评估的目的。首先采用综合轮廓法(IP)、样本熵(Samp EN)和平滑非线性能量算子(SNEO)三种方法分别检测仿真步行状态下,下肢双侧腓肠肌激活时的sEMG信号,并对这些算法得到的结果进行精度和运算时间的比较研究,最后确定了三种算法中性能比较优良的SNEO算法,然后再利用实测的小儿脑瘫患者的sEMG信号,对患儿步态活动段进行检测和标定。研究结果表明:三种算法在sEMG步态活动段的划分中精度的差异没有统计学意义,但SNEO算法具有运算速度快的优点,适用于sEMG信号的步态活动段检测;小儿脑瘫患者的脑瘫程度与其sEMG信号的步态活动段平均长度呈正相关关系,三种不同程度脑瘫患儿的步态活动段长度差异具有统计学意义。通过本文研究结果,我们提出或许可以考虑将步态活动段平均长度作为一种评估脑瘫程度的辅助定量化指标的新思路。

In this study, surface electromyography （sEMG） of the lower limbs of cerebral-palsy （CP） subjects in gait cycle was recorded and its parameters of gait cycle characters were analyzed to assess their clinical severity. Three algorithms, including integrated profile （IP）, sample-entropy （SampEN） and smooth nonlinear energy operator （SNEO） algorithm, were applied to calculate the duration of walking sEMG segments in simulated SEMG signals. After that, the efficiency and accuracy were compared among these three algorithms. SNEO was then selected as the optimal algorithm among the three algorithms and employed for real sEMG signal processing of CP subjects. The results indicated that there was no significant difference in the accuracy of sEMG segement detection for the three algorithms. However, the computation speed of SNEO algorithm was much faster than those of the others and thus it was a suitable algorithm for detecting walking sEMG segments of CP subjects. In addition, the positive correlation was found between the clinical severity and the mean duration of walking sEMG segments in CP subjects. The results indicated that there was a significant difference in the three groups of CP subjects with different levels of severity. Our findings showed that the mean duration of walking sEMG segments could be considered as an assistant index to evaluate the clinical severity of CP subjects.