Prisk G Kim, Hammer J, Newth Christopher J L
Division of Physiology, Department of Medicine, University of California at San Diego, La Jolla, California 92093-0931, USA.
Pediatr Pulmonol. 2002 Dec;34(6):462-72. doi: 10.1002/ppul.10204.
Respiratory motion measured by respiratory inductance plethysmography often deviates from the sinusoidal pattern assumed in the traditional Lissajous figure (loop) analysis used to determine thoraco-abdominal asynchrony, or phase angle phi. We investigated six different time-domain methods of measuring phi, using simulated data with sinusoidal and triangular waveforms, phase shifts of 0-135 degrees, and 10% noise. The techniques were then used on data from 11 lightly anesthetized rhesus monkeys (Macaca mulatta; 7.6 +/- 0.8 kg; 5.7 +/- 0.5 years old), instrumented with a respiratory inductive plethysmograph, and subjected to increasing levels of inspiratory resistive loading ranging from 5-1,000 cmH(2)O. L(-1). sec(-1). The best results were obtained from cross-correlation and maximum linear correlation, with errors less than approximately 5 degrees from the actual phase angle in the simulated data. The worst performance was produced by the loop analysis, which in some cases was in error by more than 30 degrees. Compared to correlation, other analysis techniques performed at an intermediate level. Maximum linear correlation and cross-correlation produced similar results on the data collected from monkeys (SD of the difference, 4.1 degrees ) but all other techniques had a high SD of the difference compared to the correlation techniques. We conclude that phase angles are best measured using cross-correlation or maximum linear correlation, techniques that are independent of waveform shape, and robust in the presence of noise.
通过呼吸感应体积描记法测量的呼吸运动，常常偏离传统李萨如图形（环）分析中假定的正弦模式，而传统李萨如图形分析用于确定胸腹不同步，即相位角φ。我们使用具有正弦和三角波形、0 - 135度相移以及10%噪声的模拟数据，研究了六种不同的测量φ的时域方法。然后将这些技术应用于11只轻度麻醉的恒河猴（猕猴；体重7.6 ± 0.8千克；年龄5.7 ± 0.5岁）的数据，这些猴子配备了呼吸感应体积描记仪，并承受从5 - 1000 cmH₂O·L⁻¹·sec⁻¹范围递增的吸气阻力负荷。互相关和最大线性相关获得了最佳结果，与模拟数据中的实际相位角相比误差小于约5度。环分析的表现最差，在某些情况下误差超过30度。与相关性相比，其他分析技术表现处于中等水平。最大线性相关和互相关对从猴子收集的数据产生了相似的结果（差异的标准差为4.1度），但与相关性技术相比，所有其他技术的差异标准差都很高。我们得出结论，使用互相关或最大线性相关来测量相位角是最好的，这些技术与波形形状无关，并且在存在噪声的情况下具有鲁棒性。
