Non-Invasive Wideband Radiometer for Accurate Core Temperature Monitoring

项目概要/摘要 临床研究表明，非常需要在整个围手术期监测核心温度 所需精度 <0.5oC。准确快速地检测超出预期范围的核心温度可以 减少不良反应的可能性，其后果可能包括增加住院率 患者死亡的费用（例如，恶性高热期间）。不幸的是，目前测量核心的方法 温度呈现出侵入性和准确性之间的权衡，并表明需要探索新的 解决方案。金标准食管、鼻咽和肺动脉温度计具有侵入性，非侵入性 适用于所有手术或术前/术后；皮肤表面温度计不能反映核心温度 并受环境影响；零热通量温度计不适合高体温 变化且不适用于深低温；最先进的辐射计误差达 1°C 至 2°C 充其量是临床上不可接受的。本研究的目的是探索一种可行性 替代辐射测量技术，利用宽带测量的创新，正向建模 分层组织和干仿生天线可实现非侵入性、准确且实时的核心温度 监控。假设低频和高频将推断出深层和深层的温度。 近表面组织分别，并且它们的后处理将提供核心的准确测量 温度（0.5oC 以内），实时，并且跨越任何感兴趣的温度范围，经头部验证 模仿幻象。这项研究意义重大，因为它揭示了以前不存在的知识 宽带辐射计模型/算法和天线设计，实现非侵入式、准确的核心温度 监控。该辐射计预计将成为手术室、整个手术室急需的补充设备。 围手术期及其他过程（例如癌症诊断）。期望最终将设备连接到 其他非侵入性监测仪（例如心脏麻醉中的脑血氧计），以开发新的 更可靠、更及时地检测并发症的标记物。在目标 1 中，宽带辐射测量模型和 将开发天线。重点是翻译已成功实施的模型 过去用于将层状冰原的温度推断为层状头部介质。此类模型从未 已在医学辐射测量中使用。然后将确定最佳频率范围，并且 仿生天线将被设计成适应这种带宽，同时表现出前所未有的辐射 效率。在目标 2 中，我们的集成辐射计将在准确模拟的头部模型上进行验证 生物温度流动和介电特性。仿生天线将被制造并连接到 辐射计，并用于验证：a）从建模中获得的亮度温度光谱，以及b） 假设检索核心温度的精度为 0.5oC。该宽带辐射计的可行性 组织模拟模型将成为未来人类研究的基础。

PROJECT SUMMARY / ABSTRACT Clinical studies indicate a great need for monitoring core temperature throughout the perioperative process at a desired accuracy of <0.5oC. Accurate and fast detection of core temperatures beyond the intended ranges can decrease the likelihood of adverse effects, the outcomes of which may range from increased hospitalization costs to patient fatalities (e.g., during malignant hyperthermia). Unfortunately, current means of measuring core temperature present a tradeoff between invasiveness and accuracy and suggest a need for exploring novel solutions. Gold standard esophageal, nasopharynx and pulmonary artery thermometers are invasive and not feasible for all surgeries nor pre-/post-operatively; skin surface thermometers do not reflect core temperature and are affected by the environment; zero-heat-flux thermometers are unsuitable for intense body temperature changes and do not work for deep hypothermia; and state-of-the-art radiometers are inaccurate by 1oC to 2oC at best, and, hence, clinically unacceptable. The goal of this research is to explore the feasibility of an alternative radiometry technique that leverages innovations in broadband measurements, forward modeling of layered tissues, and dry biomimetic antennas to enable non-invasive, accurate, and real-time core temperature monitoring. The hypothesis is that low and high frequencies will infer the temperature from across deep and near-surface tissues, respectively, and that their post-processing will provide accurate measures of core temperature (within 0.5oC), in real-time, and across any temperature range of interest, as validated upon head- emulating phantoms. This study is significant because it reveals previously nonexistent knowledge on wideband radiometer models/algorithms and antenna designs for non-invasive and accurate core temperature monitoring. This radiometer is envisioned to be a much needed addition to the operating room, across the perioperative process, and beyond (e.g., cancer diagnostics). The expectation is to eventually link the device to other non-invasive monitors (e.g., cerebral oximeters in cardiac anesthesia) towards the development of new markers for more reliable and timely detection of complications. In Aim 1, wideband radiometry models and antennas will be developed. The focus entails translating models that have been successfully implemented in the past for inferring the temperature of layered ice sheets into layered head media. Such models have never been used in the context of medical radiometry. Optimal frequency ranges will then be identified, and biomimetic antennas will be designed to accommodate this bandwidth while exhibiting unprecedented radiation efficiency. In Aim 2, our integrated radiometer will be validated upon head phantoms that accurately emulate biological temperature flow and dielectric properties. Biomimetic antennas will be fabricated, connected to radiometers, and used to validate: a) the brightness temperature spectrum obtained from modeling, and b) the hypothesized accuracy of 0.5oC in retrieving the core temperature. Feasibility of this wideband radiometer in tissue-emulating phantoms will form the basis of future studies on human subjects.