Biomedical Instrumentation Laboratory, Institute of Biology and Faculty of Engineering, State University of Rio de Janeiro, Brazil.
Pulmonary Function Laboratory, Faculty of Medical Sciences, State University of Rio de Janeiro, Brazil.
Respir Physiol Neurobiol. 2014 Feb 1;192:39-47. doi: 10.1016/j.resp.2013.12.004. Epub 2013 Dec 12.
We investigated the influence of airway obstruction in the complexity of the airflow pattern in COPD and its use as a marker of disease activity. The sample entropy (SampEnV') and the variability (SDV') of the airflow pattern were measured in a group of 88 subjects with various levels of airway obstruction. Airway obstruction resulted in a reduction in the SampEnV' (p<0.0001) that was significantly correlated with spirometric indices of airway obstruction (R=0.50, p<0.001). The early adverse effects in mild airway obstruction were detected by the SampEnV' with an accuracy of 84%. SDV' increased with airway obstruction (p<0.002). We conclude that (1) the airflow patterns in COPD exhibit reduced complexity compared with healthy subjects; (2) this reduction in complexity is proportional to airway obstruction; and (3) the evaluation of SampEnV' may provide novel respiratory biomarkers suitable to facilitate the diagnosis of respiratory abnormalities in COPD.
我们研究了气道阻塞对 COPD 气流模式复杂性的影响及其作为疾病活动标志物的作用。在一组 88 名气道阻塞程度不同的患者中，测量了样本熵（SampEnV'）和气流模式的变异性（SDV'）。气道阻塞导致 SampEnV'降低（p<0.0001），与气道阻塞的肺功能指标呈显著相关（R=0.50，p<0.001）。SampEnV'可以在轻度气道阻塞的早期发现不良影响，其准确率为 84%。SDV'随气道阻塞而增加（p<0.002）。我们的结论是：（1）COPD 的气流模式与健康受试者相比表现出复杂性降低；（2）这种复杂性的降低与气道阻塞成比例；（3）SampEnV'的评估可能提供新的呼吸生物标志物，有助于促进 COPD 呼吸异常的诊断。
