肌肉疲劳微机监测系统

A MICROCOMPUTER-BASED MUSCULARFATIGUE MONITORING SYSTEM

本文提出了一个在线实时估计肌电信号功率谱中值频率的算法。根据此算法,研制了一个肌肉疲劳监测系统,所使用的微型机是Intel SDK-86,通过跟踪中值频率的变化,该系统可以定量地评价局部肌肉疲劳。

<ABSTRACT> As muscular contraction is sustained,the power spectrum of myoelectric signal is compressed towards the lower frequencies, This spectral shift has been found by some investigators to be associated with localized mus- cular fatigue and conduction velocity decrease of muscle fiber action poten- tial. The median frequency of myoelectric signal power spectrum appears to be the preferred parameter to monitor the spectral compression. This paper presents a algorithm which provides estimation of median frequency in real-time. The algorithrn is hased on digital filters implemen- ted by controlling the sample frequency to adjust the cutoff frequencies of the filters effectively and simply. The error caused by quantization of sample frequency is analysed and discussed. This algorithm offers some advantages as compared to the previous algorithms [4], [5]. Based on this algorithm,a system for monitoring muscular fatigue is deviced with single board computer (Intel SDK-86 ). The system perferms a quantitative assessment of localized muscular fatigue by tracking changes in median frequncy parameter of myoelectric signal power spectrtum. Finally, results are presented and discussed which are obtained from inputing in to the system some test signals (sine waves, white noise) as well as from somatic muscular fatigue experiments. The authors suggest that this system is reliable for clinical applica- tion.