气道分中央气道和周围小气道。气道阻力80%在中央气道,20%在周围小气道。一般周围小气道的疾病不易测出,致使慢性支气管炎等气道疾病得不到早期诊治。我们根据流速容量曲线在低肺容量(75%以下)时呼气流速不受胸内压影响的原理,将肺量计用最大呼气后期流速测定了正常人和慢性支气管炎患者各50例,认为本法简便易行,具有临床意义,现介绍于下。 Airway sub-central airway and the surrounding small airways. Airway resistance 80% in the central airway, 20% in the small airways around. Small airways around the general disease is not easy to measure, resulting in chronic bronchitis and other airway diseases can not get early diagnosis and treatment. According to the principle of flow velocity volume curve in the low lung capacity (75%) when the expiratory flow rate from the impact of intrathoracic pressure, the spirometer with the maximum expiratory flow rate measured in normal and chronic bronchitis in 50 patients, This law is simple and easy to understand, of clinical significance, is introduced below.