基于肌电样本熵的反馈式电刺激仪的研究

Research on feedback type electric stimulator based on myoelectric sample entropy

为提供一种用于肛门成形术的术中入路引导和术后康复训练的仪器,设计了一种基于表面肌电信号样本熵的反馈式神经肌肉电刺激仪。通过控制光耦隔离的H桥电路的导通方向、导通时间来精准控制刺激脉冲的脉宽与极性;刺激脉冲的幅值通过微控制器控制DAC模块输出特定电压作用于压控恒流电路来实现。引入了肌电样本熵分析表面肌电信号的复杂性,用于评估刺激训练后肌肉收缩力的康复效果,并将其作为反馈量用于刺激参数的调节。采用开发的系统样机进行了验证试验,由实验可知,该样机实现了刺激脉冲的多参数可调以及输出脉冲的恒流效果;对采集到的表面肌电信号进行基于样本熵的复杂度计算,拟合得到复杂度与肌力之间呈现线性关系。本文设计的电刺激仪采用样本熵来对sEMG-肌力进行定量评价,为反馈式电刺激仪提供了一种新的刺激参数调节方法及神经肌肉功能的评估方法,对神经肌肉系统的临床诊断和康复训练具有一定指导意义。

In order to provide an instrument for intraoperative stimulation and postoperative rehabilitation of anal sphincter training for imperforate anus,a feedback neuromuscular electrostimulation device based on surface myoelectric signal sample entropy was designed.The pulse width and polarity of the stimulation pulse are precisely controlled by controlling the conduction direction and conduction time of the H-bridge circuit isolated by the optocoupler;the amplitude of the stimulation pulse is controlled by the microcontroller to output a specific voltage to the voltage-controlled constant current.The circuit is implemented.The complexity of the surface electromyography signal of the EMG sample entropy was introduced,which was used to evaluate the rehabilitation effect of muscle contraction force after stimulation training,and used as feedback amount for the adjustment of stimulation parameters.The verification experiment was carried out with the developed system prototype.It is known from the experiment that the prototype realizes the multi-parameter adjustment of the stimulation pulse and the constant current effect of the output pulse;the complexity calculation based on the sample entropy is performed on the acquired surface electromyogram signal.Fitting gives a linear relationship between complexity and muscle strength.The electrostimulator designed in this paper uses sample entropy to quantitatively evaluate sEMG-muscle strength,and provides a new stimulation parameter adjustment method and neuromuscular function evaluation method for feedback electro-stimulator,and clinical diagnosis of neuromuscular system.And rehabilitation training has certain guiding significance.