Miniature EPR sensor for on-site oximetry

摘要 了解组织氧水平对诊断、预后、 以及治疗包括心血管疾病、癌症和创伤在内的多种病理 治愈然而，对于能够测量患者体内组织氧的装置存在未满足的需求 具有合理程度的准确性、可靠性和鲁棒性。虽然有很多方法 被认为适用于患者的氧气测量，但它们缺乏进行 重复测量以监测治疗期间或治疗后的时间变化。电子 基于顺磁共振（EPR）的血氧测定法提供了某些独特的优势， 方法，包括高准确性，高灵敏度pO 2和高功能特异性。 不幸的是，基于EPR的技术用于临床目的仍然需要解决一个问题， 一些基本问题，最明显的是现有硬件带来的限制。 大多数传统的EPR系统是大的、笨重的单元， 磁极重要的是，患者必须被带到EPR设施进行氧气测量。 因此，EPR硬件的相当大的变化是必要的，使这项技术更 从临床的角度来看，吸引人的并且可在床边或治疗部位获得。总目标 该探索性项目的一个重要目标是开发一种高度创新的微型EPR设备， 重复监测患者深部组织pO 2。我们建议建立一个独特的自我- 包含紧凑型EPR传感器系统，称为可植入式氧传感器，可用于 在诊所的网站。与需要大的外部磁体的现有EPR系统相比， 我们的方法将使用一个超小的永久磁铁，它将被集成在一个谐振器中 拿着氧气传感器一体化植入式装置直径为2 mm， 6毫米长，将由一个新型的紧凑型光谱仪驱动，基于最先进的领域 可编程门阵列（FPGA）电子器件。该两年期项目的具体目标是： 构建一个微型EPR传感器使用永磁体，环隙谐振器，和氧- 传感晶体嵌入在硅聚合物中，连接到一个紧凑、简单和经济实惠的 脉冲EPR光谱仪;（ii）验证EPR传感器的体外和体内性能， 动物模型这一独特的设备将能够对深层地下水进行连续的现场实时监测， 组织pO 2，并可能成为临床使用的重要工具，以优化各种治疗， 治疗结果。

Abstract Knowledge of tissue oxygen level has enormous clinical significance in the diagnosis, prognosis, and treatment of several pathologies including cardiovascular disease, cancer, and wound healing. However, there is an unmet need for devices that can measure tissue oxygen in patients with a reasonable degree of accuracy, reliability, and robustness. Although a number of methods are considered applicable for oxygen measurements in patients, they lack the ability to make repeated measurements to monitor temporal changes during or post-therapy. Electron paramagnetic resonance (EPR)-based oximetry offers certain unique advantages over other methods, including high accuracy, high sensitivity to pO2 and high functional specificity. Unfortunately, the use of EPR-based techniques for clinical purposes still needs to address a number of fundamental issues, most notably the restrictions that arise from existing hardware. Most conventional EPR systems are large, bulky units with restrictive spacing between the magnet poles. Importantly, patients must be brought to the EPR facility for oxygen measurements. Hence, considerable changes in EPR hardware are necessary to make this technology more appealing and available by bedside or at treatment site from a clinical standpoint. The overall goal of this exploratory project is to develop a highly innovative miniature EPR device capable of repeated monitoring of deep tissue pO2 in patients. We propose to construct a unique self- contained compact EPR sensor system, called implantable oxygen sensor that can be used on site in the clinic. In contrast to the existing EPR system, which requires a large external magnet, our approach will use an ultra-small permanent magnet, which will be integrated within a resonator holding the oxygen-sensing probe. The all-in-one implantable unit will be of 2-mm diameter and 6-mm length and will be driven by a novel compact spectrometer, based on state-of-the-art field programmable gate array (FPGA) electronics. The specific aims of the two-year project are: (i) To construct a miniature EPR sensor using permanent magnets, loop-gap resonator, and oxygen- sensing crystal embedded in a silicone polymer attached to a compact, simple and affordable pulse EPR spectrometer; (ii) To validate the EPR sensor performance in vitro and in vivo using animal model. This unique device will enable continuous on-site and real-time monitoring of deep- tissue pO2 and may become a vital tool for clinical use to optimize various therapies for improving treatment outcomes.