Device and algorithm for oxygenation quantification in the brain

大脑氧合定量装置和算法

• 批准号: 526380-2018
• 负责人: Murari, Kartikeya
• 金额: $ 1.82万
• 依托单位: University of Calgary
• 依托单位国家: 加拿大
• 项目类别: Engage Grants Program
• 财政年份: 2018
• 资助国家: 加拿大
• 起止时间: 2018-01-01 至 2019-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=660444
• 关键词: Device; algorithm; oxygenation; quantification; brain

Oxygenation, a measure of oxygen carried in the blood, is an important biomarker because brain activity**induces local changes in it. Thus, it reflects brain energy metabolism and is widely used in animal models to**monitor neuronal activity and to investigate neurovascular coupling, the relationship between electrical and**vascular activity. Radiological methods to measure oxygenation, e.g. functional magnetic resonance imaging**(fMRI) and positron emission tomography (PET), are costly and require animals to be restricted or**anesthetized, greatly limiting the scope of studies. Optical methods like near-infrared spectroscopy (NIRS) and**intrinsic optical signal imaging (IOSI), have reduced spatial resolution or limited depth penetration.**This research aims to develop optical techniques and a device for quantifying oxygenation from a**highly-localized volume in the deep brain structures of freely-moving rodents. We propose using reflectance**spectroscopy with a single fiber probe to deliver and collect light in the brain area of interest. Depth penetration**is achieved by stereotaxically implanting the fiber probe. We will select a few illumination wavelengths which**optimize the separation between chromophores and provide optimized sensitivity to functional changes. A**lock-in amplifier along with frequency-modulated multi-wavelength illumination will be used to reconstruct**spectral information of the reflected light. An empirical model based on Monte Carlo simulations will be used**to extract the oxygenation and other hemodynamic parameters from the spectra. The system will be**characterized and verified in a custom designed optical phantom.**The proposed study will create a new device enabling oxygenation measurements in a very localized volume**over time at any depth in freely-moving animals. It will allow functional monitoring of hemodynamics when**the animal is in a more natural state, compared to restrained or anesthetized. When combined with other optical**monitoring modalities, e.g., fiber photometry, the proposed system can be used to correct for hemodynamic**artifacts, which can corrupt other optical signals.

氧合是血液中氧含量的一种量度，是一种重要的生物标志物，因为大脑活动 ** 会引起局部氧含量的变化。因此，它反映了大脑的能量代谢，并被广泛用于动物模型中，以 ** 监测神经元活动，并研究神经血管耦合，即电活动和血管活动之间的关系。测量氧合的放射学方法，例如功能性磁共振成像（fMRI）和正电子发射断层扫描（PET），成本很高，需要限制动物或麻醉动物，极大地限制了研究范围。光学方法，如近红外光谱（NIRS）和 ** 内在光学信号成像（IOSI），具有降低的空间分辨率或有限的深度穿透。这项研究旨在开发光学技术和设备，用于量化自由移动啮齿动物脑深部结构中高度局部化体积的氧合。我们建议使用反射 ** 光谱与一个单一的光纤探头提供和收集光在大脑区域的利益。通过立体定位植入光纤探针实现深度穿透 **。我们将选择几个照明波长，这些波长 ** 优化发色团之间的分离，并提供对功能变化的优化灵敏度。将使用 ** 锁相放大器沿着频率调制的多波长照明来重建反射光的 ** 光谱信息。将使用基于蒙特卡罗模拟的经验模型 ** 从光谱中提取氧合和其他血液动力学参数。系统将在定制设计的光学体模中进行 ** 表征和验证。**这项拟议的研究将创建一种新的设备，使氧合测量在一个非常局部的体积 ** 随着时间的推移，在任何深度的自由移动的动物。当 ** 动物处于比束缚或麻醉状态更自然的状态时，它将允许对血流动力学进行功能监测。当与其他光学 ** 监测模式结合时，例如，光纤测光，所提出的系统可以用于校正血液动力学伪影，其可以破坏其他光学信号。