呼吸力学参数的频率依赖性研究

Study of Frequence Dependence of Pulmonary Mechanical Parameters

用谱估计方法对10名健康被试者平静呼吸时的呼吸气体流率、食管压力信号进行了分析,求出自基频至3倍频的肺阻力(R_L)及动态顺应性(C_(dyn))。结果如下:①C_(dyn)在10名被试者均表观为随呼吸信号谐波频率的增高而降低。在基频,2倍频和3倍频下,C_(dyn)的均值依次为,4.3±1.3、2.4±0.6及2.3±0.5(kPa^(-1)·L)②R_L在6名被试者表现为随呼吸信号谐波频率的增高而降低;2名被试者表现为随呼吸信号谐波频率的增高而增高。在基频、2倍频及3倍频下,R_L的均值依次为,0.14±0.05、0.13±0.05及0.12±0.05(kPa·L^(-1)·s)用谱估计方法分析C_(dyn)的频率依赖特性对小气道病变的早期诊断可能有一定意义。

The spontaneous respiratory flow rate (V(t)) and the esophageal pressure (P(t)) were analyzed in 10 health subjects with the method of power spectrum estimation (PSE). The pulmonary resistance (RL) and the dynamic compliance (Cdyn) have been obtained from the 1st, 2nd and the 3rd harmonics of the V(t) and P(t). The results showed that (1) in 10 subjects, the Cdyn was lowered with the increased harmonic frequency of the (t) and P(t). The mean values of the Cdyn for the 1st, 2nd and the 3rd harmonics were 4.3±1.3, 2.4±0.6 and 2.3±0.5 (kPa-1·L) respectively; (2) in 8 subjects, the RL. was lowered with the increased harmonic frequency of the V(t) and P(t); in 2 subjects, the RL increased with the increased harmonic frequency of the V(t) and P(t). The mean values of the RL for the 1st, 2nd and the 3rd harmonics were 0.14±0.05, 0.13±0.05 and 0.12±0.05 (kPa·L-1·s) respectively. The frequency dependence of the Cdyn analyzed by the method of PSE might be significant for the early diagnosis of the small airway diseases.