Wouters E F
Department of Pulmonary Diseases, State University Limburg, Maastricht, The Netherlands.
Exp Lung Res. 1990 Jan;16(1):25-40. doi: 10.3109/01902149009064697.
The forced oscillation technique is a noninvasive and effort-independent test to characterize the mechanical impedance of the respiratory system. By applying a complex signal, the frequency-dependent behavior of the respiratory system can be measured over an extended spectrum. For clinical practice, the input impedance is used most frequently; pressure and flow are measured at the same place. The impedance can be partitioned into a real part or resistance and an imaginary part or reactance. At low frequencies, reactance is determined by the capacitance of the system and at high frequencies by the inertial properties of the system. Equipment and impedance data in normal subjects and patients with chronic obstructive pulmonary disease are discussed. The frequency-dependent behavior of the respiratory system is described with the use of an electrical model characterized by partitioning of airway resistance and the presence of shunt compliance represented by the compliance of the intrathoracic airway walls. Influences of peripheral resistance, airway compliance, lung volumes, chest wall and pulmonary resistance, and resistance of the cheeks and upper airways are analyzed. Input impedance can be applied to the detection of bronchoconstriction and bronchodilation, but this technique is suitable for detecting early airway abnormalities caused by smoking or occupational hazards.
强迫振荡技术是一种用于表征呼吸系统机械阻抗的非侵入性且与用力无关的测试方法。通过施加一个复合信号，可以在较宽的频谱范围内测量呼吸系统的频率依赖性行为。在临床实践中，最常使用输入阻抗；压力和流量在同一位置进行测量。阻抗可分为实部即电阻和虚部即电抗。在低频时，电抗由系统的电容决定，在高频时由系统的惯性特性决定。文中讨论了正常受试者和慢性阻塞性肺疾病患者的设备及阻抗数据。利用一个电学模型来描述呼吸系统的频率依赖性行为，该模型的特征是气道阻力的划分以及由胸内气道壁顺应性所代表的分流顺应性的存在。分析了外周阻力、气道顺应性、肺容积、胸壁和肺阻力以及脸颊和上气道阻力的影响。输入阻抗可用于检测支气管收缩和舒张，但该技术适用于检测由吸烟或职业危害引起的早期气道异常。
