Non-Invasive Wideband Radiometer for Accurate Core Temperature Monitoring

用于精确监测核心温度的非侵入式宽带辐射计

• 批准号: 10039648
• 负责人: Asimina Kiourti
• 金额: $ 7.24万
• 依托单位: OHIO STATE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-07-01 至 2022-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10039648
• 关键词: Adult; Adverse effects; Affect; Air; Algorithms; Anatomic Models; Anatomy; Anesthesia procedures; Biological; Biomimetics; Body Temperature Changes; Bolus Infusion; Brain; Cancer Diagnostics; Cardiac; Cardiac Surgery procedures; Cerebrum; Clinical; Clinical Research; Data; Detection; Development; Devices; Environment; Equilibrium; Esophagus; Event; Exhibits; Family suidae; Fatty acid glycerol esters; Frequencies; Future; Goals; Gold; Hair; Head; Health; Hospital Costs; Human; Ice; Ice Cover; Knowledge; Link; Malignant hyperpyrexia due to anesthesia; Measurement; Measures; Medical; Modeling; Monitor; Nasopharynx; Operating Rooms; Operative Surgical Procedures; Outcome; Patients; Pediatrics; Perioperative; Postoperative Period; Process; Pulmonary artery structure; Radiation; Radiometry; Reporting; Research; Scalp structure; Skin; Surface; Surgical Blood Loss; Surgical Wound Infection; Techniques; Temperature; Thermometers; Thick; Time; Tissue Model; Tissues; Transfusion; Translating; Validation; Variant; Water; animal tissue; base; beef; cost; density; design; dielectric property; expectation; human subject; innovation; interest; natural hypothermia; non-invasive monitor; novel; novel marker; radio frequency; stroke patient; transmission process

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.

项目摘要/摘要 临床研究表明，在围手术期过程中，非常需要以适当的温度监测核心温度。 所需精度<0.5oC。对超出预期范围的核心温度的准确和快速检测可以 降低不良反应的可能性，其结果可能包括增加住院治疗 患者死亡的成本（例如，在恶性高热期间）。不幸的是，目前测量核心的方法 温度在侵袭性和准确性之间存在折衷，并建议需要探索新的 解决方案黄金标准食道、鼻咽和肺动脉温度计是侵入性的， 适用于所有手术，也不适用于术前/术后;皮肤表面温度计不反映核心温度 并且受环境影响;零热通量温度计不适合高体温 变化，不适用于深度低温;最先进的辐射计不准确1 oC至2 oC 因此在临床上无法接受本研究的目的是探索一种 替代辐射测量技术，利用宽带测量的创新， 分层组织和干仿生天线，以实现非侵入性，准确和实时的核心温度 监测.该假说认为，低频和高频将推断出来自深部和深部的温度， 近地表组织，分别，他们的后处理将提供准确的措施，核心 温度（0.5 ℃以内），实时，并在任何温度范围内的利益，经验证的头部- 模仿幻影这项研究意义重大，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，可实现无创且准确的核心温度 监测.该辐射计被设想为手术室非常需要的附加设备， 围手术期过程，以及以后（例如，癌症诊断）。我们的期望是最终将设备连接到 其它非侵入式监视器（例如，脑血氧计在心脏麻醉）的发展， 更可靠和及时地检测并发症的标志物。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， 过去用于推断分层冰盖的温度到分层的头部介质。这种模式从来没有 被用于医学辐射测量。然后将确定最佳频率范围， 仿生天线将被设计为适应这种带宽，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头部幻影上进行验证， 生物温度流动和介电性质。仿生天线将被制造出来，连接到 辐射计，并用于验证：a）从建模获得的亮度温度谱，和B） 在反演核心温度时，假设准确度为0.5oC。这种宽带辐射计在 组织仿真幻影将成为未来人体研究的基础。