A miniaturised laser isotope ratiometer for early diagnosis of sepsis by exhaled breath analysis

本项目旨在开发一种快速准确诊断败血症的原型医疗仪器。败血症是一种严重的感染并发症，如果不及时治疗，可能导致多器官衰竭和死亡。在英国，每年有44000人死于败血症，其中14000人被认为是可以通过改进诊断和减少开始治疗的延误来预防的。治疗延误仅仅几个小时就会对患者的结果产生重大影响。目前的脓毒症检测需要将患者的血液或其他液体样本送到实验室进行分析。目前的检测有两个缺点：首先，发送样本进行分析的过程会带来延迟，这反过来又降低了成功治疗的机会；其次，无法对患者进行持续监测，因此可能会错过病情的发作。卢瑟福阿普尔顿实验室（RAL）的研究人员开发了一种名为激光同位素比率仪（LIR）的仪器，该仪器应该能够通过分析患者呼出气体的成分来识别败血症的早期阶段。患者呼出的自然形成的二氧化碳比例的变化可以表明脓毒症的存在。LIR将能够通过分析呼出气体所吸收的红外光的细微变化来实时检测这些变化。至关重要的是，该仪器将对分析结果进行解释，并将其作为患者是否患有败血症的简单“是”或“否”指示呈现给医务人员。这种方法是非侵入性的，对于那些不能自己呼吸的最严重的病人，LIR可以连接到呼吸机上，以提供连续监测。在项目期间，RAL的仪器科学家将与伦敦国王学院（KCL）的临床医生合作，确定LIR是否可以提供一种识别败血症患者的可靠方法。这将通过临床试验来完成，KCL将提供匿名样本袋，其中包含患有和不患有败血症的患者的呼出气体，由RAL的LIR进行盲测。LIR已经在其他应用领域得到了成功的验证，并正在石油和天然气行业进行商业化开发。在该项目中，RAL的工作将包括准备用于呼吸分析的现有小型LIR版本，表征其性能，以及开发测试方案以确保准确性和可靠性。如果使用样品袋进行的初步测试成功，将有机会将LIR部署在国王学院医院的临床环境中进行进一步测试。这将使人们更好地了解该方法的有效性，包括潜在的成本节约。

This project aims to develop a prototype medical instrument for the rapid and accurate diagnosis of sepsis. Sepsis is a serious complication of infections, and without timely treatment can lead to multiple organ failure and death. In the UK 44,000 deaths per annum are attributed to sepsis, and 14,000 of those are thought to be preventable with improved diagnosis and reduced delays in beginning treatment. Delays in treatment of just a few hours can have a significant impact on the outcome for the patient. Current tests for sepsis require samples of blood or other fluid from the patient to be taken to a laboratory for analysis. There are two drawbacks associated with current testing: Firstly, the process of sending samples for analysis introduces delay, which in turn reduces the chances of successful treatment; secondly, patients cannot be monitored continuously and so the onset of the condition may be missed.Researchers at the Rutherford Appleton Laboratory (RAL) have developed an instrument called a laser isotope ratiometer (LIR) that should be able to identify the very early stages of sepsis by analysing the composition of exhaled breath from the patient. Changes in the ratio of naturally occurring forms carbon dioxide exhaled by patients can indicate the presence of sepsis. The LIR will be capable detecting these changes in real time by analysing subtle changes in the infrared light absorbed by the exhaled breath. Crucially the results of this analysis will be interpreted by the instrument and presented to medical staff as a simple "yes" or "no" indication of whether the patient has sepsis or not. The method is non-invasive and, for the sickest patients that are not able to breathe for themselves, the LIR could be attached to ventilators to provide continuous monitoring.During the project the instrument scientists at RAL will work with clinicians at King's College London (KCL) to determine whether the LIR can provide a reliable way of identifying patients with sepsis. This will be done through clinical trials where KCL will provide anonymised sample bags containing exhaled breath from patients with and without sepsis for blind testing by the LIR at RAL.The LIR has been successfully demonstrated in other application areas, and is being exploited commercially for the oil and gas industry. During this project the work at RAL will include preparation of an existing miniaturised version of the LIR for breath analysis, characterization of its performance, and development of the test protocol to ensure accuracy and reliability. If initial tests using sample bags are successful there will be an opportunity for the LIR to be deployed in a clinical environment at King's College Hospital for further testing. This will enable a better idea of the effectiveness of the approach, including potential cost savings.