Craven N, Sidwall G, West P, McCarthy D S, Cherniack R M
Am Rev Respir Dis. 1976 Apr;113(4):445-9. doi: 10.1164/arrd.1976.113.4.445.
A computerized system has been developed to analyze the parameters that can be derived from the nitrogen washout curve. Analog signals for air flow, volume, and nitrogen concentration are entered either on-line or off-line into a 24,000 mini-computer. The program calculates vital capacity, total lung capacity, and residual volume, as well as the slope of phase III, closing volume in liters, total lung capacity, residual volume, closing capacity, closing volume/vital capacity ratio, and closing capacity/total lung capacity ratio. Validation tests showed excellent correlation between hand- and computer-calculated values of closing volume(r=0.864), vital capacity (r=0.997), total lung capacity (r=0.991), and slope of phase III (R=0.926). We concluded that the computerized system for analysis of the expired nitrogen washout curve is as reliable as hand calculations and is immeasurably faster.
已开发出一种计算机系统，用于分析可从氮洗脱曲线得出的参数。气流、体积和氮浓度的模拟信号可在线或离线输入到一台24000小型计算机中。该程序可计算肺活量、肺总量、残气量，以及III期斜率、以升为单位的闭合气量、肺总量、残气量、闭合容量、闭合气量/肺活量比值和闭合容量/肺总量比值。验证测试表明，手工计算和计算机计算的闭合气量（r = 0.864）、肺活量（r = 0.997）、肺总量（r = 0.991）和III期斜率（R = 0.926）之间具有极好的相关性。我们得出结论，用于分析呼出氮洗脱曲线的计算机系统与手工计算一样可靠，而且速度快得无法估量。
