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

基本信息

批准号：
10194492
负责人：
Asimina Kiourti
金额：
$ 7.21万
依托单位：
OHIO STATE UNIVERSITY
依托单位国家：
美国
项目类别：
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/10194492
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

项目摘要

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；最先进的辐射计的误差为 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。