Abrahams N, Fisk G C, Churches A E, Loughman J, Vonwiller J B, Agzarian J, Harrison G A
Anaesth Intensive Care. 1975 Nov;3(4):284-94. doi: 10.1177/0310057X7500300402.
Instrument errors that can occur when pneumotachography is used during Intermittedt Positive Pressure Ventilation (IPPV) have been described previously (Kafer 1973). Our efforts to eliminate these errors led to the discovery of further inaccuracies, which appear to be due to the design of the differential pressure transducers used with pneumotachograph head. A system was used in which a sine-wave pump delivered a constant tidal volume to a dummy lung, the tidal volume being measured by means of a pneumotachograph. Using Grass, Statham and Devices differential pressure transducers, the volume recorded as leaving the dummy lung was consistently greater than that recorded as entering, and changing the pneumatic polarity of the differential pressure transducer produced large differences in the recorded volume. In some cases the error was greater than the volume being measured. There would seem to be several causes of such errors. The Sanborn 270 differential pressure transducer and the Greer micromanometer appeared to be free of these artifacts. The results of this study throw into doubt much previously published work using pneumotachography during IPPV.
间歇性正压通气（IPPV）期间使用肺量计可能出现的仪器误差先前已有描述（卡费尔，1973年）。我们消除这些误差的努力导致发现了进一步的不准确性，这似乎是由于与肺量计探头一起使用的差压传感器的设计所致。使用了一个系统，其中正弦波泵向模拟肺输送恒定潮气量，潮气量通过肺量计测量。使用格拉斯、斯塔瑟姆和德维塞斯差压传感器时，记录的离开模拟肺的体积始终大于记录的进入模拟肺的体积，并且改变差压传感器的气动极性会导致记录体积出现很大差异。在某些情况下，误差大于所测量的体积。此类误差似乎有几个原因。桑伯恩270差压传感器和格里尔微压计似乎没有这些伪影。这项研究的结果使先前许多关于IPPV期间使用肺量计的已发表工作受到质疑。
