The bedside Exhaled Drug MONitor – EDMON measures exhaled propofol in ppb_v every minute based on multi-capillary column – ion mobility spectrometry (MCC-IMS). The MCC pre-separates gas samples, thereby reducing the influence of the high humidity in human breath. However, preliminary analyses identified substantial measurement deviations between dry and humid calibration standards. We therefore performed an analytical validation of the EDMON to evaluate the influence of humidity on measurement performance. A calibration gas generator was used to generate gaseous propofol standards measured by an EDMON device to assess linearity, precision, carry-over, resolution, and the influence of different levels of humidity at 100% and 1.7% (without additional) relative humidity (reference temperature: 37°C). EDMON measurements were roughly half the actual concentration without additional humidity and roughly halved again at 100% relative humidity. Standard concentrations and EDMON values correlated linearly at 100% relative humidity (R²=0.97). The measured values were stable over 100min with a variance ≤ 10% in over 96% of the measurements. Carry-over effects were low with 5% at 100% relative humidity after 5min of equilibration. EDMON measurement resolution at 100% relative humidity was 0.4 and 0.6 ppb_v for standard concentrations of 3 ppb_v and 41 ppb_v. The influence of humidity on measurement performance was best described by a second-order polynomial function (R²≥0.99) with influence reaching a maximum at about 70% relative humidity. We conclude that EDMON measurements are strongly influenced by humidity and should therefore be corrected for sample humidity to obtain accurate estimates of exhaled propofol concentrations.

床边呼出药物监测仪– EDMON 以 ppb _v为单位测量呼出的异丙酚每分钟基于多毛细管柱 - 离子迁移谱（MCC-IMS）。MCC预分离气体样本，从而降低人体呼吸中高湿度的影响。然而，初步分析发现干燥和潮湿校准标准之间存在显着测量偏差。因此，我们对 EDMON 进行了分析验证，以评估湿度对测量性能的影响。校准气体发生器用于生成由 EDMON 设备测量的气态丙泊酚标准品，以评估线性度、精度、残留、分辨率以及 100% 和 1.7%（无额外）相对湿度下不同湿度水平的影响（参考温度：37°C）。EDMON 测量值大约是实际浓度的一半，没有额外的湿度，并且在 100% 相对湿度下再次大约减半。标准浓度和 EDMON 值在 100% 相对湿度下呈线性相关 (R²=0.97)。在超过 96% 的测量中，测量值在 100 分钟内保持稳定，方差≤ 10%。平衡 5 分钟后，在 100% 相对湿度下，残留影响很低，为 5%。EDMON 在 100% 相对湿度下的测量分辨率为 0.4 和 0.6 ppb_v为 3 ppb _v和 41 ppb _v的标准浓度。湿度对测量性能的影响最好用二阶多项式函数 (R²≥0.99) 来描述，其影响在大约 70% 的相对湿度时达到最大值。我们得出结论，EDMON 测量值受湿度的强烈影响，因此应针对样品湿度进行校正，以获得呼出异丙酚浓度的准确估计值。