Optical monitoring of cerebral oxygenation in infants

描述（由申请人提供）：缺氧通常是缺氧和灌注不足共同作用的结果，通常是引发生化级联反应的主要事件，导致围产期脑病中不可逆的脑损伤。该项目的长期目标是开发一种新型近红外光谱 (NIRS) 装置，用于连续监测新生儿大脑中的区域组织饱和度 (St02)、动脉饱和度 (Sa02) 和静脉饱和度 (Sv02)。这种设备有可能在不可逆的结构损伤发生之前检测到脑组织的受损情况，从而可以进行及时和具体的干预。我们方法的新颖性与以下假设有关：对 NIRS 数据进行适当的时间分析可以产生三种不同的氧合测量结果：（1）来自光信号时间平均值的 St02； (2) Sa02，来自脉冲频率下光吸收的振荡分量； (3) Sv02 来自呼吸频率处光吸收的振荡分量。该项目的短期目标是表征脑氧合的 NIRS 测量特征，并确定用于无创脑血氧测定的 NIRS（在仪器和数据处理方面）最有效的实际实施。具体来说，我们的目标是 1) 研究脑组织、动脉血管室和静脉血管室中血红蛋白氧合的局部测量之间的关系，以及 2) 进行脑氧合的空间分辨测量以定位脑损伤区域。为了实现我们的短期目标，我们建议对动物模型（仔猪）进行测量，在其中我们可以诱导血红蛋白氧合水平在大范围内发生变化，我们可以在其中进行血液稀释实验，在其中我们可以诱发局灶性脑损伤，并且我们可以从血液样本的气体分析中获得 Sa02 和 Sv02 的侵入性读数。最后，我们将测试我们提出的用于人类新生儿脑血氧测定的 NIRS 方法。这项研究的完成将促进大脑 NIRS 血氧测定法的表征、多模式光学血氧测定法（同时局部测量 St02、Sa02 和 Sv02）的发展，并确定最有效的非侵入性方法。连续监测新生儿脑氧合。

DESCRIPTION (provided by applicant): Oxygen deprivation, typically the result of a combination of hypoxia and hypoperfusion, is often the primary event setting off a biochemical cascade that leads to irreversible brain injury in perinatal encephalopathy. The long-term objective of this project is the development of a novel near-infrared spectroscopy (NIRS) device for the continuous monitoring of the regional tissue saturation (St02), arterial saturation (Sa02), and venous saturation (Sv02) in the neonate's brain. Such a device could potentially detect brain tissue compromise before the development of irreversible structural damage, thus allowing for timely and specific intervention. The novelty of our approach relates to the hypothesis that an appropriate temporal analysis of NIRS data can yield three different oxygenation measurements: (1) St02 from the temporal average of the optical signal; (2) Sa02 from the oscillating component of the optical absorption at the pulse frequency; (3) Sv02 from the oscillating component of the optical absorption at the respiratory frequency. The short-term goals of this project are to characterize NIRS measurements of cerebral oxygenation and to identify the most effective practical implementation of NIRS (in terms of instrumentation and data processing) for non-invasive cerebral oximetry. In particular, we aim to 1 ) investigate the relationship between the local measurements of the hemoglobin oxygenation in the cerebral tissue, in the arterial vascular compartment, and in the venous vascular compartment, and 2) perform spatially resolved measurements of cerebral oxygenation to localize areas of brain damage. To achieve our short-term goals, we propose to perform measurements on an animal model (piglets) where we can induce changes in the hemoglobin oxygenation levels over a large range, where we can perform hemodilution experiments, where we can induce focal brain injury, and where we have access to invasive readings of Sa02 and Sv02 from the gas analysis of blood samples. Finally we will test our proposed NIRS approach to cerebral oximetry on human neonates. The completion of this study will lead to the characterization of NIRS oximetry of the brain, to the development of multimode optical oximetry (simultaneous local measurement of St02, Sa02, and Sv02), and to the identification of the most effective approach to the non-invasive. continuous monitoring of cerebral oxygenation in neonates.