Institut für Lasermedizin, Universität Düsseldorf, D-40225 Düsseldorf, Germany.
J Breath Res. 2007 Sep;1(1):014002. doi: 10.1088/1752-7155/1/1/014002. Epub 2007 Jul 11.
Despite the growing number of reports on breath CO measurements, the development of rapid and sensitive analysis techniques for measurements of this breath constituent still remains a challenge. We demonstrate the application of infrared laser spectroscopy for exhaled CO analysis. The breath samples are analyzed in real-time during single exhalations by means of cavity ring-down spectroscopy. This is an ultra-sensitive laser-based method for the analysis of trace gases with precision on the ppb level (parts per billion). The noise-equivalent CO level of this method is 7 ppb Hz(-1/2); the time resolution is around 1 s. The expirograms were recorded with exhalation flow rates varying from 4 l min(-1) up to 50 l min(-1). Alveolar phase (phase III) of expiration shows a remarkable flow-rate dependence. Also, expirograms were recorded after a breath holding time between 0 s and 60 s. The normalized slope of the alveolar plateau (S(n)) was determined, which is between 0.004 l(-1) and 0.15 l(-1).
尽管关于呼吸 CO 测量的报道越来越多，但开发用于测量这种呼吸成分的快速和灵敏分析技术仍然是一个挑战。我们展示了红外激光光谱在呼气 CO 分析中的应用。通过腔衰荡光谱法，在单次呼气过程中实时分析呼吸样本。这是一种基于超灵敏激光的痕量气体分析方法，具有 ppb 级（十亿分之几）的精度。该方法的噪声等效 CO 水平为 7 ppb Hz(-1/2)；时间分辨率约为 1 秒。呼出气量从 4 l min(-1)到 50 l min(-1)变化时，记录呼气量图。肺泡相（第 III 相）的呼气表现出显著的流速依赖性。此外，还记录了在 0 s 到 60 s 之间屏住呼吸后的呼出气量图。确定了肺泡平台的归一化斜率（S(n)），其值在 0.004 l(-1)和 0.15 l(-1)之间。
