Schweitzer T W, Fitzgerald J W, Bowden J A, Lynne-Davies P
J Appl Physiol Respir Environ Exerc Physiol. 1979 Jan;46(1):152-65. doi: 10.1152/jappl.1979.46.1.152.
The inspiratory diaphragmatic EMG was recorded via esophageal electrodes in six normal subjects. The EMG and ECG signals were analyzed by power density spectral analysis, before and after band-pass filtering (20--1,600 Hz). The EMG spectrum was concentrated in the bandwidth 25--250 Hz. Electrode motion introduced a significant artifact only at low frequencies. The ECG spectrum was also concentrated at lower frequencies, but substantial power from the cardiac signal spilled over across most of the EMG spectrum. Band-pass filtering was therefore effective in minimizing the former but not the latter. Of the various power and frequency parameters used to quantitate the EMG spectrum, the most stable was the centroid frequency. This was reproducible within and between subjects, and was not affected by changing tidal volume or inspiratory flow rate.
通过食管电极记录了6名正常受试者吸气时的膈肌肌电图。在带通滤波（20 - 1600赫兹）前后，通过功率密度谱分析对肌电图和心电图信号进行了分析。肌电图频谱集中在25 - 250赫兹的带宽内。电极运动仅在低频时引入了显著的伪迹。心电图频谱也集中在较低频率，但心脏信号的大量功率溢出到了大部分肌电图频谱范围内。因此，带通滤波在最小化前者方面有效，但对后者无效。在用于量化肌电图频谱的各种功率和频率参数中，最稳定的是质心频率。它在受试者内部和之间都具有可重复性，并且不受潮气量或吸气流量变化的影响。
