MEFV曲线是诊断小气道疾患的敏感指标之一,已为国内外学者公认。在国外已有先进的流速仪直接记录,数字和图形也能打印,由于经济条件的限制国内除少数机构外,一般很难用外汇购得国外进口仪器,因而MEFY曲线难以推广使用。结合国情,郭先健等应用“平均法”从FVC曲线来计算MEFV曲线的几十个代表点, MEFV curve is one of the sensitive indicators of diagnosis of small airway disease, has been recognized by scholars at home and abroad. In foreign countries, advanced flow meters have been recorded directly. Numbers and graphics can also be printed. Due to the restriction of economic conditions, it is generally difficult to purchase imported instruments by foreign exchange except for a few institutions in China. Therefore, the MEFY curve is difficult to popularize. Combined with the national conditions, Guo Xianjian and other “average method” from the FVC curve to calculate the MEFV curve of dozens of representative points,