Cairns A M, Road J D
Division of Respiratory Medicine, Vancouver Hospital & Health Sciences Centre, BC, Canada.
Respir Physiol. 1998 Jun;112(3):305-13. doi: 10.1016/s0034-5687(98)00032-2.
Power spectra were derived from the diaphragm electromyogram (EMG) in anesthetized rabbits subjected to inspiratory resistive loading (IRL) with airway pressure swings of 40-60 cm H2O for 20 min to 2 h. Shifts in the centroid frequencies of the power spectra were found to be associated with the appearance of power spectral peaks in the range of 105-140 Hz, termed high-frequency oscillation, or HFO. Such peaks have been described before in phrenic nerve activity and in the diaphragm EMG. However, these peaks have not previously been connected with the shifts in centroid frequency seen during loaded breathing. Although such changes in frequency content have been taken to indicate fatigue in the diaphragm, we find that HFO can also cause a shift in centroid frequency during loaded breathing, an effect whose relation to fatigue has yet to be established.
对麻醉兔施加吸气阻力负荷（IRL），气道压力波动为40 - 60 cm H₂O，持续20分钟至2小时，从膈肌肌电图（EMG）得出功率谱。发现功率谱质心频率的变化与105 - 140 Hz范围内功率谱峰值的出现有关，该峰值范围被称为高频振荡（HFO）。之前在膈神经活动和膈肌肌电图中已描述过此类峰值。然而，这些峰值此前尚未与负荷呼吸期间观察到的质心频率变化联系起来。尽管频率成分的这种变化被认为表明膈肌疲劳，但我们发现高频振荡在负荷呼吸期间也可导致质心频率变化，其与疲劳的关系尚待确定。
