Interferometric Speckle Visibility Spectroscopy for Brain Activity Associated Cerebral Blood Flow Monitoring

用于脑活动相关脑血流监测的干涉散斑可见光谱

• 批准号: 10294139
• 负责人: CHANGHUEI YANG
• 金额: $ 28.78万
• 依托单位: CALIFORNIA INSTITUTE OF TECHNOLOGY
• 依托单位国家: 美国
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-09-30 至 2023-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10294139
• 关键词: Address; Blood; Blood flow; Brain; Categories; Cerebrovascular Circulation; Clinical; Data; Detection; Diffuse; Hemoglobin; Human; Light; Location; Magnetic Resonance Imaging; Measurement; Measures; Metabolic; Methods; Monitor; Motor; Motor Cortex; Near-Infrared Spectroscopy; Optical Methods; Optics; Output; Oxygen; Pattern; Positron-Emission Tomography; Radiation; Research; Sampling; Sensitivity and Specificity; Signal Transduction; Site; Spectrum Analysis; Speed; Surface; System; Technology; Testing; Time; Ultrasonography; Update; Visual; Visual Cortex; absorption; advanced system; base; blood flow measurement; blood oxygen level dependent; cost; density; design; diffuse optical tomography; improved; instrument; light weight; neurovascular; novel; portability; prototype; response; scale up; temporal measurement; transmission process; uptake

Abstract Optical monitoring of brain activities is intrinsically associated with a range of operational advantages: a. non-ionizing and safe radiation, b. simple and relatively lightweight apparatus, c. readily available commercial optical advanced systems that can be cross adapted for our usage. While the prevalent optical brain monitoring methods are based on measuring blood oxygenation level dependent (BOLD) signal associated with the absorption spectral shift of blood to oxygen level changes, optical methods based on measuring cerebral blood flow (CBF) signal associated with scattering dynamics that scale with the blood flow in the brain may provide a promising alternative with certain advantages. Some of these advantages include: 1) Provide neurovascular information that is complementary to BOLD information – the combination of which can reveal a more complete picture of the neurovascular interactions. For example, the combination of BOLD and CBF measurements may be used to compute metabolic oxygen uptake rate in the brain. 2) As CBF measurements do not depend on the absorption spectrum of hemoglobin, there is a potential that CBF methods can penetrate deeper into the brain by using longer wavelengths. 3) Optical CBF methods are relatively simple to implement. We envision that a high-density full brain surface coverage CBF instrument can be implemented in a portable fashion. For this R21 project, we propose to develop and evaluate a novel CBF measurement method, known as interferometric speckle visibility spectroscopy (iSVS), for the task of high sensitivity and multi-point brain monitoring. The iSVS method is substantially different from the current optical CBF method of choice – diffuse correlation spectroscopy (DCS). Whereas DCS requires sampling of the speckle fluctuations at a rate much faster than the decorrelation time (typically ~ 100 microseconds), iSVS can perform measurements at a much slower rate of ~ 100 Hz and still provide superior measurement SNR by exploiting the multiple pixels available on commercial cameras. We propose to implement and test a parallel CBF monitoring prototype that can monitor 50 locations simultaneously with an update rate of 100 Hz. We will then compare sensitivity and specificity of the developed iSVS to relative CBF changes evoked by simple motor and visual tasks in the primary motor and visual cortex of the human brain. If successful, the technology will fill a vital measurement gap that existing optical, MRI, ultrasound and PET methods have not been able to address.

摘要 光学监测大脑活动本质上与一系列操作优势相关： A.非电离和安全辐射；B.简单且相对轻便的设备；C.现成的 商业光学先进系统，可以根据我们的使用进行交叉调整。而流行的光学技术 大脑监测方法基于测量血氧水平依赖(BOLD)信号 与血液吸收光谱向氧气水平的变化有关，光学方法基于 测量脑血流量(CBF)信号，该信号与与血流量成比例的散射动力学有关 可能会提供一种有希望的替代方案，具有一定的优势。其中一些优势包括： 1)提供补充粗体信息的神经血管信息--它们的组合 可以揭示神经血管相互作用的更完整的图景。例如，粗体的组合 脑血流量的测量可以用来计算大脑的代谢性摄氧率。2)作为CBF 测量不依赖于血红蛋白的吸收光谱，有可能使CBF 这种方法可以通过使用更长的波长深入大脑。3)光学CBF方法有 实现起来相对简单。我们设想一种高密度、全脑表面覆盖的CBF仪器 可以以可移植的方式实现。 对于这个R21项目，我们建议开发和评估一种新的CBF测量方法，称为 作为干涉散斑可见度光谱(ISVS)，用于高灵敏度和多点脑的任务 监控。ISVS方法与当前选择的光学CBF方法--漫反射方法有很大不同 相关光谱学(DCS)。然而，分布式控制系统需要对散斑波动进行采样 比去相关时间(通常约100微秒)更快，ISV可以以更快的速度执行测量 较低的约100赫兹的速率，并通过利用可用的多个像素仍然提供卓越的测量SNR 在商用摄像机上。 我们建议实现和测试一个并行的CBF监测原型，可以监测50个位置 同时更新速率为100赫兹。然后我们将比较所开发的敏感性和特异性 简单运动和视觉任务引起的初级运动和视皮层相对脑血流量变化的ISV 人类大脑的。如果成功，这项技术将填补现有光学、核磁共振、 超声波和正电子发射计算机断层扫描(PET)方法还无法解决这一问题。