Development of EPR and NIR Oximetry for Diabetic Foot

描述(由申请人提供)：糖尿病显著增加了微血管和大血管疾病的风险，这是这种日益普遍的疾病的高发病率和死亡率的主要因素。糖尿病患者足部溃疡愈合不良、感染和恶化的原因是血液循环受损导致的组织氧合不良，这是基本的病理生理因素。在目前的临床实践中，还没有可用于直接测定组织含氧量的技术。相反，临床医生需要依靠各种方法来尝试测量血流灌注，如多普勒超声，或组织氧合的间接测量，经皮氧气测量(TCO2)。后者探测到氧气通过加热到42-44℃的皮肤扩散。C，它与组织中的实际pO2有复杂的关系。该项目将应用两项新兴技术：电子顺磁共振血氧仪(EPR)和近红外光谱(NIR)，更直接、更可靠地测量健康志愿者的组织氧合。最终目的是将这项技术推广到糖尿病患者，用于疾病的临床管理。EPR是一种新的血氧仪，它直接测量组织的氧含量，而近红外血氧仪表征血管内血红蛋白的数量和饱和度，因此这两种技术的结合将提供有关氧气输送和局部浓度的补充信息，提供更完整的组织氧合情况。EPR和NIR的主要潜在优势是它们提供了以前没有的信息，即直接的组织氧含量，并且可以在很长一段时间内非侵入性地获得有意义的重复测量。这些信息将非常有助于确定疾病的状态，并确定治疗干预对组织氧合的影响，以及氧合与疾病进展之间的关系。已经取得了有希望的初步结果，表明在人体内跟踪组织氧多年是可行的。如果这些技术的前景得以实现，临床医生将拥有一种基于基础病理生理学的新的强大工具来管理周围血管疾病。

DESCRIPTION (provided by applicant): Diabetes markedly raises the risk of microvascular and macrovascular diseases, major contributors to higher morbidity and mortality in this increasingly prevalent disorder. The resulting poor tissue oxygenation due to compromised circulation accounts for the poor healing, infection, and deterioration of foot ulcers in diabetics; this is the basic underlying pathophysiological factor. In current clinical practice, there is no technique available for direct determination of tissue oxygen content. Instead, clinicians need to rely on various methods that attempt to measure perfusion such as Doppler ultrasound, or an indirect measure of tissue oxygenation, transcutaneous oxygen measurement (TcO2). The latter detects oxygen diffusing through skin warmed to 42-44? C by the instrument, which has a complex relationship to the actual pO2 in the tissue. This project will apply 2 emerging techniques; electron paramagnetic resonance (EPR) oximetry and near infrared spectroscopy (NIR) to measure tissue oxygenation more directly and reliably in healthy volunteers. The ultimate aim is to extend the techniques to diabetic patients for clinical management of the disease. EPR is a new oximetry modality that directly measures tissue oxygen content and NIR oximetry characterizes the amount and saturation of intravascular hemoglobin, so a combination of these 2 techniques will provide complementary information about oxygen delivery and local concentration, providing a more complete picture of the tissue oxygenation. The major potential advantages of EPR and NIR are that they provide information not previously available, namely direct tissue oxygen content, and that meaningful repeated measurements can be obtained non-invasively over a long period of time. This information would be extremely useful for characterizing the status of the disease, and to determine the effects of therapeutic intervention on tissue oxygenation, and the relationship between oxygenation and progression of the disease. Promising preliminary results have been obtained, indicating the feasibility of following tissue oxygen in humans for years. If the promise of these techniques is fulfilled, clinicians will have a new powerful tool for management of peripheral vascular disease, based on fundamental pathophysiology.