Joynt R L, Erlandson R F, Rourke M
Department of PM&R, Wayne State University, Detroit, MI 48201.
Arch Phys Med Rehabil. 1988 Jul;69(7):517-23.
Computer simulation is a process that appears to have wide application in many disciplines. Electromyographic (EMG) interference patterns can be computer-synthesized by inputting parameters of individual motor unit action potentials (MUAPs) such as amplitude, duration, and phases, and recruitment parameters of number of motor units, and the firing rate and its standard deviation. The resulting simulated EMG interference patterns can then be used to test hypotheses regarding the effect of alteration of the individual MUAP parameters on the interference pattern. An example of the usefulness of simulation is demonstrated by the analysis of the simulated patterns by the Fast Fourier Transform (FFT), which indicates that the major frequency band in the FFT results from the duration of the individual phases of the MUAP. The motor unit's recruitment rate is superimposed on the FFT envelope in the low-frequency end. The variability of the firing rate influences the distinctness of the low-frequency peaks. The MUAP amplitude and number of motor units in the recruitment pattern are reflected in the FFT power. Simulation appears to be a useful tool for further investigation and development of EMG signal analysis techniques.
计算机模拟是一个似乎在许多学科中都有广泛应用的过程。肌电图（EMG）干扰模式可以通过输入单个运动单位动作电位（MUAP）的参数（如幅度、持续时间和相位）、运动单位数量的募集参数以及放电频率及其标准差来进行计算机合成。然后，生成的模拟EMG干扰模式可用于检验关于单个MUAP参数改变对干扰模式影响的假设。通过快速傅里叶变换（FFT）对模拟模式进行分析，展示了模拟的实用性，这表明FFT中的主要频段来自MUAP各个相位的持续时间。运动单位的募集率叠加在低频端的FFT包络上。放电频率的变异性影响低频峰值的清晰度。募集模式中的MUAP幅度和运动单位数量反映在FFT功率中。模拟似乎是进一步研究和开发EMG信号分析技术的有用工具。
