论文部分内容阅读
肺泡气通过时间(transit time,以下简称TT)指用力呼气时,不同肺容积单位肺活量从肺泡排出体外所需的平均时间,从时间肺活量曲线上测得。由 Fish 等于1974年首先提出,这是一项较能反映大、小气道功能的检查,其中对早期小气道病变的检测尤为敏感。原理和概况肺脏是进行气体交换的器官,肺内与外界存在动态压力差,导致气体流动。气流速度(V)与驱动压(P)、气道阻力(R)的关系可由函数式
Pulmonary transit time (TT) refers to the average time required for excretion of vital capacity of different lung volume units from the alveoli when forced exhaled, as measured from the time vital capacity curve. First proposed by Fish et al. In 1974, this is a test that reflects the function of large and small airways, and is particularly sensitive to the detection of early small airway disease. Principle and overview The lungs are organs for gas exchange. Dynamic pressure differences exist between the lungs and the outside world, resulting in gas flow. The relation between the air velocity (V) and the driving pressure (P) and the airway resistance (R) can be expressed by the formula