MWIR LASER-BASED BREATH SENSOR FOR ASTHMA GRADING

用于哮喘分级的 MWIR 激光呼吸传感器

• 批准号: 6073854
• 负责人: DAVID I. ROSEN
• 金额: $ 10.64万
• 依托单位: PHYSICAL SCIENCES, INC
• 依托单位国家: 美国
• 财政年份: 2000
• 资助国家: 美国
• 起止时间: 2000-09-10 至 2001-09-09
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6073854
• 关键词: asthma; bioengineering /biomedical engineering; biomedical equipment development; breath composition; infrared radiation; laser spectrometry; lasers; nitric oxide; respiratory gas analyzer; respiratory gas level

Recent studies have shown that the mixed expired air from asthmatics contains elevated levels of nitric oxide (NO) compared to that recovered from nonasthmatic individuals. These and other observations have led to the hypothesis that NO produced enzymatically by the airway may serve as an indicator of the inflammatory microenvironment of the airway. To better answer this question, a new type of exhaled breath analyzer is needed. Currently available NO analyzers cannot adequately resolve the temporal profile of NO concentration vs expired volume over the course of a single expiration. Physical Sciences Inc. (PSI) proposes to develop and demonstrate a tunable MWIR laser sensor for the rapid, non-invasive measurement of NO and other selected breath species in human breath. The laser source will be built around a type of room-temperature, tunable MWIR semiconductor lasers. In Phase I we will combine the new source with existing ultrasensitive detection technology to demonstrate high speed, in situ measurements of ppb levels of NO in human breath. We will also show the feasibility of incorporating simultaneous dynamic measurements of breath CO2. The goal is to develop an instrument that can yield such measurements at equal to or greater than 10 Hz sampling rates in sample volumes equal to or less than 25 ml. In Phase II, a prototype instrument will be delivered to a leading asthma research group for clinical studies. The study objective will be to non- invasively determine the extent to which the increased NO levels observed in samples of mixed expired air of patients with asthma are due to increased NO in the deadspace fraction versus alveolar fraction of the lung. If the level of NO in the deadspace fraction can be shown to correlate with asthma status, then the basis for an unambiguous, "non-invasive" method of measuring airway inflammation will be established. PROPOSED COMMERCIAL APPLICATIONS: A "non-invasive" and unambiguous method for measuring airway inflammation would be of great value in asthma clinics all over the country. The proposed sensor is also likely to prove useful for assessments of oxidative stress in human subjects.

最近的研究表明，与非哮喘患者呼出的混合气体相比，哮喘患者呼出的混合气体中一氧化氮 (NO) 的含量较高。这些和其他观察结果得出这样的假设：气道酶促产生的 NO 可以作为气道炎症微环境的指标。为了更好地回答这个问题，需要一种新型的呼气分析仪。目前可用的 NO 分析仪无法充分解析单次呼气过程中 NO 浓度与呼气量的时间关系。 Physical Sciences Inc. (PSI) 提议开发并演示一种可调谐 MWIR 激光传感器，用于快速、非侵入性地测量人类呼吸中的一氧化氮和其他选定的呼吸物质。该激光源将围绕一种室温可调谐中波红外半导体激光器构建。在第一阶段，我们将把新源与现有的超灵敏检测技术结合起来，展示对人类呼吸中 ppb 级 NO 的高速原位测量。我们还将展示同时动态测量呼吸二氧化碳的可行性。我们的目标是开发一种仪器，能够以等于或大于 10 Hz 的采样率、在等于或小于 25 ml 的样本量中进行此类测量。在第二阶段，原型仪器将交付给领先的哮喘研究小组进行临床研究。该研究的目的是非侵入性地确定哮喘患者混合呼出气体样本中观察到的 NO 水平增加在多大程度上是由于死腔部分与肺泡部分中 NO 的增加所致。如果可以证明死腔部分中的 NO 水平与哮喘状态相关，那么将建立测量气道炎症的明确的“非侵入性”方法的基础。拟议的商业应用：一种测量气道炎症的“非侵入性”且明确的方法对于全国各地的哮喘诊所具有重要价值。所提出的传感器也可能被证明可用于评估人类受试者的氧化应激。