基于sEMG的联合收获机驾驶人腰部肌肉疲劳研究

A Study of Lumbar Muscle Fatigue of Combine Harvester Drivers Based on sEMG

为探究联合收获机驾驶人驾驶过程中腰部肌肉变化的生理信息,采用对照方法研究了联合收获机驾驶人腰部肌肉疲劳的演化过程。分别采集了120 min收获驾驶和静坐过程中10名联合收获机驾驶人腰部左右竖脊肌的表面肌电信号,探究不同组别腰部左右竖脊肌表面肌电信号的iEMG (integrated electromyogram)、RMS (root mean square)、MPF、MF和样本熵随驾驶时间的变化规律,探讨各特征参数表征腰部疲劳的效度。结果表明:120 min联合收获机收获驾驶操作后腰部左右竖脊肌产生疲劳;对照组腰部左右竖脊肌表面肌电信号的时域、频域和非线性指标在任务前后无显著差异(P>0.05),实验组腰部左右竖脊肌表面肌电信号的iEMG和RMS随驾驶时间显著上升(P<0.05),而MPF、MF和样本熵显著下降(P<0.05);与线性指标相比,样本熵的变异系数最小,能够较好地表征腰部疲劳的生理信息,稳定性较好。

To explore the physiological information of lumbar muscle changes of combine harvester drivers during the driving process, the evolution process of lumbar muscle fatigue of combine harvester drivers was studied by contrast. The surface electromyographic signals of the left and right erector spinae muscle of 10 combine harvester drivers were collected respectively in the process of 120 min harvest driving and 120 min sitting. The change rule of iEMG, RMS, MPF, MF and sample entropy of the surface electromyographic signals with driving time was analyzed in different groups. The validity representing lumbar fatigue of characteristic parameters was investigated. The results demonstrate that the left and right erector spinae muscles are submitted to fatigue after 120 min harvest driving operation. In the control group, there were no significant differences in time domain, frequency domain and non-linear indexes of the surface electromyography signals of the left and right erector spinal muscles before and after the task(P > 0.05). In the experimental group, the iEMG and RMS of the surface electromyography of lumbar erector spine muscle increased significantly with the driving time(P < 0.05),while the MPF, MF and sample entropy decreased significantly(P < 0.05). Compared with linear index, the variation coefficient of sample entropy is the smallest, which can better represent the physiological information of lumbar fatigue and has good stability.