Marchand M, Teculescu D, Pham Q T, Dao P L, Henquel J C
Rev Mal Respir. 1985;2(4):215-21.
The classical assembly used for the single breath nitrogen washout implies the manipulation of valves by the operator, a perfect coordination of respiratory maneuvers by the subject and a rigid standardization of the interpretation of the tracings by the technicians doing the calculations. We present a computerized analysis of the single breath nitrogen test, based on a microcomputer (Apple II 48K) solving most of the problems above. The opening of the valves is operated by the computer program recorded on disk; the tidal volume and expiratory flow are displayed on the screen on line allowing the subject to comply with the requested limits; the nitrogram is displayed at the end of the test, allowing the technician to explain the errors (if any). The program then goes on computing the slope of phase III, the closing volume, total lung capacity and its subdivisions for each trial, and the average values for two or three trials accepted by the operator. The system worked satisfactorily during a pilot study in healthy adults (variability and reproducibility) and was particularly useful in a field survey of children and adolescents.
用于单次呼吸氮冲洗的传统装置需要操作人员手动操作阀门，受试者要完美协调呼吸动作，并且进行计算的技术人员对描记图的解读要严格标准化。我们基于一台微型计算机（苹果II型48K）对单次呼吸氮试验进行了计算机化分析，解决了上述大部分问题。阀门的开启由记录在磁盘上的计算机程序控制；潮气量和呼气流量在线显示在屏幕上，以便受试者遵守要求的限度；氮浓度图在试验结束时显示，使技术人员能够解释误差（如有）。然后，该程序继续计算每次试验的第三相斜率、闭合气量、肺总量及其细分值，以及操作人员认可的两到三次试验的平均值。在一项针对健康成年人的初步研究中（变异性和可重复性），该系统运行良好，并且在对儿童和青少年的现场调查中特别有用。
