Krueger-Ziolek Sabine, Schullcke Benjamin, Gong Bo, Müller-Lisse Ullrich, Moeller Knut
Institute of Technical Medicine, Furtwangen University, Jakob-Kienzle-Straße 17, 78054 Villingen-Schwenningen, Germany. Department of Radiology, LMU University of Munich, Ziemssenstrasse 1, 80336 Munich, Germany3.
Physiol Meas. 2017 Jun;38(6):1214-1225. doi: 10.1088/1361-6579/aa69d5.
Evaluating the lung function in patients with obstructive lung disease by electrical impedance tomography (EIT) usually requires breathing maneuvers containing deep inspirations and forced expirations. Since these maneuvers strongly depend on the patient's co-operation and health status, normal tidal breathing was investigated in an attempt to develop continuous maneuver-free measurements.
Ventilation related and pulsatile impedance changes were systematically analyzed during normal tidal breathing in 12 cystic fibrosis (CF) patients and 12 lung-healthy controls (HL). Tidal breaths were subdivided into three inspiratory (In1, In2, In3) and three expiratory (Ex1, Ex2, Ex3) sections of the same amplitude of global impedance change. Maximal changes of the ventilation and the pulsatile impedance signal occurring during these sections were determined (▵I and ▵I ). Differences in ▵I and ▵I among sections were ascertained in relation to the first inspiratory section. In addition, ▵I /▵I was calculated for each section.
Medians of changes in ▵I were <0.05% in all sections for both subject groups. Both groups showed a similar pattern of ▵I changes during tidal breathing. Changes in ▵I first decreased during inspiration (In2), then increased towards the end of inspiration (In3) and reached a maximum at the beginning of expiration (Ex1). During the last two sections of expiration (Ex2, Ex3) ▵I changes decreased. The CF patients showed higher variations in ▵I changes compared to the controls (CF: -426.5%, HL: -158.1%, coefficient of variation). Furthermore, ▵I /▵I significantly differed between expiratory sections for the CF patients (Ex1-Ex2, p < 0.01; Ex1-Ex3, p < 0.001; Ex2-Ex3, p < 0.05), but not for the controls. No significant differences in ▵I /▵I between inspiratory sections were determined for both groups.
Differences in ▵I changes and in ▵I /▵I between both subject groups were speculated to be caused by higher breathing efforts of the CF patients due to airway obstruction leading to higher intrathoracic pressures, and thus to greater changes in lung perfusion.
通过电阻抗断层成像（EIT）评估阻塞性肺疾病患者的肺功能通常需要包含深呼吸和用力呼气的呼吸动作。由于这些动作很大程度上依赖于患者的配合和健康状况，因此对静息呼吸进行了研究，试图开发无需特定动作的连续测量方法。
系统分析了12例囊性纤维化（CF）患者和12例肺部健康对照者（HL）在静息呼吸过程中与通气相关的和搏动性阻抗变化。潮气呼吸被细分为全球阻抗变化幅度相同的三个吸气段（In1、In2、In3）和三个呼气段（Ex1、Ex2、Ex3）。确定这些段中通气和搏动性阻抗信号出现的最大变化（▵I 和▵I ）。确定各段之间▵I 和▵I 相对于第一个吸气段的差异。此外，计算每个段的▵I /▵I 。
两个受试者组所有段的▵I 变化中位数均<0.05%。两组在潮气呼吸过程中▵I 变化模式相似。▵I 变化在吸气过程中（In2）先降低，然后在吸气末期（In3）升高，并在呼气开始时（Ex1）达到最大值。在呼气的最后两段（Ex2、Ex3），▵I 变化降低。与对照组相比，CF患者的▵I 变化差异更大（CF：-426.5%，HL：-158.1%，变异系数）。此外，CF患者呼气段之间的▵I /▵I 有显著差异（Ex1-Ex2，p<0.01；Ex1-Ex3，p<0.001；Ex2-Ex3，p<0.05），而对照组没有。两组吸气段之间的▵I /▵I 无显著差异。
推测两个受试者组之间▵I 变化和▵I /▵I 的差异是由于CF患者因气道阻塞导致更高的呼吸努力，进而导致更高的胸内压，从而使肺灌注变化更大。
