参数自适应调节的肌电反馈式电刺激仪的设计  

Design of electromyography feedback electrical stimulator with adaptive parameter adjustment

作　　者：陈小月 郭旭东[1] 郝又国 CHEN Xiaoyue;GUO Xudong;HAO Youguo(School of Health Science and Engineering,University of Shanghai for Science and Technology,Shanghai 200093,China;Shanghai Putuo District People's Hospital,Shanghai 200060,China)

机构地区：[1]上海理工大学健康科学与工程学院,上海200093 [2]上海市普陀区人民医院,上海200060

出　　处：《上海理工大学学报》2023年第4期371-378,共8页Journal of University of Shanghai For Science and Technology

基　　金：上海市自然科学基金资助项目(20ZR1437700);上海市2022年度生物医药科技支撑专项(22S31902200);上海市市级科技重大专项(2021SHZDZX)。

摘　　要：功能性电刺激是脑卒中后导致的运动功能障碍患者康复治疗的有效手段,现有的功能性电刺激仪多采用被动式或参数恒定式刺激方式,治疗效果不佳。本文设计了一种基于表面肌电信号的参数自适应调节的生物反馈式电刺激仪。以放松状态和最大自主收缩状态的表面肌电信号均方根值为参考,用刺激间歇的表面肌电信号均方根值作为反馈信号调节下一刺激周期的脉宽和幅值。为了避免过度刺激造成疲劳和伤害,提出了基于特征Q值的疲劳检测算法,实时检测Q值变化并在肌肉达到疲劳阈值b时终止电刺激。实验结果:仪器可以输出频率、脉宽和幅值范围分别为1~10 Hz,0.1~5 ms,5~30 mA的刺激波形,脉宽和幅值的实际输出值与设定值之间的绝对误差分别为2.3%和2.5%;相同刺激幅值下12组负载上的电压和负载阻值线性拟合结果的相关系数为0.9997,实现了恒流输出;仪器可以根据肌电均方根值调节脉宽和幅值,在检测到肌肉达到疲劳阈值(50%)时电刺激停止。Functional electrical stimulation is an effective means of rehabilitation treatment for patients with motor dysfunction after stroke.As most of the existing functional electrical stimulators use passive or parameter invariant stimulation methods and the effect is poor,a biofeedback electrical stimulator with adaptive adjustment of parameters based on surface electromyography was designed.Root mean square(RMS)of surface electromyography(sEMG)in the relaxed state and the maximum voluntary contraction state was taken as a reference.The RMS of sEMG at the interval of stimulation was used as the feedback signal to adjust the pulse width and amplitude of the next stimulation cycle.In order to avoid fatigue and injury caused by excessive stimulation,a fatigue detection algorithm based on characteristic Q was proposed.It was detected in real time to terminate electrical stimulation when the muscle reached the fatigue threshold b.Experimental results show that the instrument can output stimulation waveforms with frequency,pulse width and amplitude ranges of 1~10 Hz,0.1~5 ms,5~30 mA respectively.The absolute errors between the actual output value and the set value of pulse width and amplitude are 2.3%and 2.5%.The correlation coefficient of the linear fitting results of voltage and load resistance on 12 groups of resistors under the same stimulation amplitude is 0.9997,and the constant current output is realized.The instrument can adjust the pulse width and amplitude according to the RMS value of sEMG,and the electrical stimulation stops when the muscle reaches the fatigue threshold(50%).

关 键 词：电刺激 表面肌电信号 生物反馈 疲劳检测 

分 类 号：TH772[机械工程—仪器科学与技术]