Time-resolved measurements of breath hydrogen sulfide

描述（由申请人提供）：硫化氢（H2S），曾经被专门确定为一种有害的有毒气体，现在被认为是无数生理功能的关键参与者。活动发生在各种各样的系统中，包括牙周、心血管、神经、炎症和胃肠道。我们已经选择了这些领域之一，并提出了新的研究，检查的作用H2S在胃肠道疾病，包括结肠炎，肠易激综合征，克罗恩病。我们计划的方法侧重于开发一种快速的光学方法来测量呼出气中的硫化氢浓度。我们预计，到第二阶段资助结束时，我们将在临床环境中展示一种紧凑的全自动仪器，该仪器可以在单个呼气中以快速响应时间报告H2S实时浓度曲线。检测灵敏度为50 ppb或更高。快速响应将允许H2S口腔贡献在时间上被解析为肺泡贡献。 我们的总体假设是，可以开发一种便携式易于使用的呼吸硫化氢监测仪来诊断和管理肠易激综合征（IBS）和炎症性肠病（IBD）。我们的具体目标是评估从IBS和IBD患者到健康对照组的呼吸，并将结果与经验证的仪器（如症状问卷和标准氢气和甲烷呼吸分析）进行比较。 所提出的呼出H2S分析方法使用称为噪声免疫、腔增强、光外差测量光谱（NICE-OHMS）的光谱技术。这项技术是大约15年前由NIST的John Hall和同事发明的。它可以对多种气体实现非凡的检测灵敏度，但被认为对于商业应用来说太困难了。我们最近通过使用为无线网络开发的低成本、低功耗电子器件简化了NICE-OHMS。现在可以制造可靠的气体商业分析仪。NICE-OHMS应可用于呼吸分析。它适用于小气体样品（~50标准。cc/呼气）并且具有快速的时间响应。完全工程化的分析仪将与台式计算机大小相当。 公共卫生相关性：呼吸分析有可能成为一种广泛使用的快速治疗监测方法。我们提出的项目侧重于检测呼吸中的硫化氢，作为监测和开发衰弱性胃肠道疾病（如肠易激综合征，炎症性肠病和克罗恩病）治疗方法的一种方式。

DESCRIPTION (provided by applicant): Hydrogen sulfide (H2S), once identified exclusively as a pernicious toxic gas, is now recognized as a key participant in a myriad of physiological functions. Activity occurs in a wide variety of systems including periodontal, cardiovascular, neurological, inflammatory, and gastrointestinal. We have selected one of these areas and propose new research for examining the role of H2S in gastrointestinal illness including colitis, irritable bowel syndrome, and Crohn's disease. Our planned approach focuses on the development of a rapid, optical method for measuring hydrogen sulfide concentrations in exhaled breath. We anticipate that, by the end of the Phase II grant, we will have demonstrated in a clinical setting a compact, fully-automated instrument that can report H2S real-time concentration profiles with fast response times within individual exhalations. Detection sensitivity will be 50 ppb or better. Fast response will allow the H2S mouth contributions to be resolved temporally for alveolar contributions. Our Overall Hypothesis is that a portable easy to use breath hydrogen sulfide monitor can be developed to diagnose and manage irritable bowel syndrome (IBS) and inflammatory bowel disease (IBD). Our Specific Aim is to evaluate breath collected from patients with IBS and IBD to healthy controls, and compare the results to validated instruments such as symptom questionnaires and standard hydrogen and methane breath analysis. The proposed exhaled H2S analysis method uses an optical spectroscopy technique call noise-immune, cavity-enhanced, optical heterodyne measurement spectroscopy (NICE-OHMS). The technique was invented about 15 years ago by John Hall and co-workers at NIST. It can achieve extraordinary detection sensitivity for a variety of gases, but has been considered too difficult for commercial applications. We recently simplified NICE-OHMS by using low-cost, low-power electronics developed for wireless networking. Reliable gas commercial analyzers can now be built. NICE-OHMS should be useful for breath analysis. It works well with small gas samples (~50 std. cc per exhalation) and has fast time response. Fully engineered analyzers will be about the size of a desktop computer. PUBLIC HEALTH RELEVANCE: Breath analysis has the potential to become a widely-used, rapid method for therapeutic monitoring. Our proposed project focuses on detection of hydrogen sulfide in breath as a way of monitoring and developing treatments for debilitating gastrointestinal diseases such as irritable bowel syndrome, inflammatory bowel disease and Crohn's disease.