Miniature EPR sensor for on-site oximetry

摘要 对组织氧水平的了解在诊断、预后、 以及几种病理疾病的治疗，包括心血管疾病、癌症和伤口 治愈。然而，对能够测量患者组织氧气的设备的需求还没有得到满足。 具有合理的准确性、可靠性和健壮性。尽管有许多方法 被认为适用于患者的氧气测量，他们缺乏使 重复测量以监测治疗过程中或治疗后的时间变化。电子 基于顺磁共振(EPR)的血氧仪具有某些独特的优势 方法具有准确性高、对氧分压敏感性高、功能特异性高等特点。 不幸的是，将基于EPR的技术用于临床目的仍然需要解决 许多基本问题，最明显的是现有硬件产生的限制。 大多数传统的EPR系统都是大而笨重的单元， 磁极。重要的是，患者必须被带到EPR设施进行氧气测量。 因此，有必要对EPR硬件进行相当大的更改，以使这项技术更 从临床的角度来看，在床边或治疗现场都有吸引力。总目标 这一探索性项目的目的是开发一种高度创新的微型EPR设备，能够 患者深部组织血氧分压的重复监测。我们建议构建一个独特的自我- 包含紧凑型EPR传感器系统，称为植入式氧气传感器，可用于 在诊所的现场。与需要大的外部磁铁的现有EPR系统相比， 我们的方法将使用一个超小的永久磁体，它将被集成在谐振器中 拿着氧气感应探头。一体式可植入装置的直径为2毫米， 6毫米长，将由一种新型紧凑型光谱仪驱动，基于最先进的领域 可编程门阵列(FPGA)电子学。这项为期两年的计划的具体目标是：(I) 利用永磁体、环隙谐振器和氧气构建了一种微型EPR传感器. 传感晶体嵌入硅胶聚合物中，附着在紧凑、简单和实惠的 脉冲EPR光谱仪；(Ii)验证EPR传感器的体内外性能 动物模型。这一独特的设备将实现对深度的持续现场和实时监控 组织PO2，可能成为临床使用的重要工具，以优化各种治疗方法，以改善 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.