Institute of Analytical and Bioanalytical Chemistry, Ulm University, D-89081 Ulm, Germany.
J Breath Res. 2018 May 29;12(3):036018. doi: 10.1088/1752-7163/aabf98.
Exhaled breath offers monitoring bio markers, as well as diagnosing diseases and therapeutic interventions. In addition, vital functions may be non-invasively monitored online. Animal models are frequently used in research for determining novel therapeutic approaches and/or for investigating biological pathways. The exhaled carbon dioxide concentration, exhaled and inhaled oxygen concentration, and the subsequent respiratory quotient (RQ) offer insight into metabolic activity. One may adapt breath sampling systems and equipment designed for human applications to large animal studies. However, such adaptations are usually impossible for small animals due to their minuscule breath volume. Here, we present a system for the online monitoring of exhaled breath in a 'mouse intensive care unit' (MICU) based on a modified Fourier-transform infrared spectrometer equipped with a substrate-integrated hollow waveguide gas cell, and a luminescence-based oxygen flow-through sensor integrated into the respiratory equipment of the MICU. Thereby, per-minute resolution of O consumption and CO production was obtained, and the 95% confidence range of the determined RQ was ±0.04 or approximately ±5% of the nominal value. Changes in the RQ value caused by intervention in either the metabolic or respiratory system may therefore reliably be detected.
呼气提供了监测生物标志物的方法，可用于诊断疾病和治疗干预。此外，重要的功能可以进行在线非侵入式监测。动物模型常用于研究确定新的治疗方法和/或研究生物途径。呼气中的二氧化碳浓度、呼气和吸入的氧气浓度以及随后的呼吸商（RQ）可以深入了解代谢活动。人们可以将专门为人体应用设计的呼吸采样系统和设备应用于大型动物研究中。然而，由于小动物的呼吸量非常小，这种适应通常是不可能的。在这里，我们提出了一种基于经过改进的傅里叶变换红外光谱仪的在线监测系统，该系统配备了基于基底集成中空波导气体池的传感器，以及集成到 MICU 呼吸设备中的基于荧光的氧气流通传感器。从而可以获得每分钟分辨率的 O 消耗和 CO 产生，并且所确定的 RQ 的 95%置信范围为±0.04 或大约±5%的标称值。因此，由于代谢或呼吸系统的干预而导致的 RQ 值的变化可以可靠地检测到。
