A transformative method for functional brain imaging with Speckle Contrast Optical Spectroscopy

摘要 在正常和病理条件下对人脑功能进行无创监测的进展将导致 突破我们对大脑在健康和疾病方面的理解，并导致设备的开发 可用于日常使用，可用于监测脑损伤或神经退行性变患者 疾病，自然环境中大脑功能的研究，以及脑机接口。在众多的 脑成像技术，功能性近红外光谱(FNIRS)是一种光学方法，可以对大脑 测定氧合(HBO)和脱氧(HBr)血红蛋白对脑激活的血流动力学反应 由于大脑的激活，浓度会发生变化。它对人群和对以下方面的研究特别有用 其他成像方式是有限的，例如功能磁共振成像(FMRI)，包括用于儿童， 婴儿，以及涉及运动和相互作用或需要高时间分辨率的研究。然而，fNIR 成年人的大脑敏感度通常在10%左右，仅靠fNIRS不能提供定量的 关于所有血流动力学参数的信息，因为它不测量脑血流量(CBF)的变化。 在这里，我们建议开发一种基于光纤的散斑对比光学光谱(SCOS)系统来测量 由于人类大脑的激活，脑血流量的变化。SCOS使用成本相对较低的互补金属氧化物- 作为探测器的半导体(CMOS)摄像机。SCOS的性能可以超过现有的光纤 人体测量脑血流对比噪声比(CNR)至少一个数量级的系统 具有同等或更低成本的规模。在UG3阶段开发的SCOS-fNIRS综合系统将提供 测量与大脑激活相关的所有血流动力学参数，最高可达3倍 与单独使用fNIRS相比，大脑敏感度提高，并允许估计诱发的变化 CMRO2。在UH3阶段开发的高密度SCOS-fNIRS系统将提供所有 具有高空间和时间分辨率的血流动力学参数。这项工作将产生一种新的方法 功能性脑成像和示范性结果，将推动其他人采用和未来的进步 以更低的成本转向可穿戴设备。

Abstract Advances in non-invasive monitoring of human brain function under normal and pathological conditions will lead to breakthroughs in our understanding of the brain in health and disease, and lead to the development of devices available for everyday use, with applications such as monitoring patients with brain injuries or neurodegenerative disease, studies of brain function in natural environments, and brain-computer interfaces. Among the various brain imaging techniques, functional near infrared spectroscopy (fNIRS) is an optical method that images the hemodynamic response to brain activation by measuring the oxy-(HbO) and deoxy-(HbR) hemoglobin concentration changes due to brain activation. It is especially useful for populations and for studies for which other imaging modalities are limited, e.g. functional magnetic resonance imaging (fMRI), including for children, infants, and studies that involve motion and interactions or require high temporal resolution. However, fNIRS brain sensitivity in adult humans is typically around 10%, and fNIRS alone does not provide quantitative information about all the hemodynamic parameters as it does not measure changes in cerebral blood flow (CBF). Here, we propose to develop a fiber-based speckle contrast optical spectroscopy (SCOS) system to measure CBF variations due to brain activation in humans. SCOS uses relatively low-cost complementary metal–oxide– semiconductor (CMOS) cameras as detectors. The performance of SCOS can surpass that of existing optical systems for human measurements of CBF in terms of contrast to noise ratio (CNR) by at least one order of magnitude with equal or less cost. The combined SCOS-fNIRS system developed in the UG3 phase will provide measurements of all the hemodynamic parameters associated with brain activation, achieve an up to 3x improvement in brain sensitivity compared with fNIRS alone, and permit estimation of evoked changes in CMRO2. The high-density SCOS-fNIRS system developed in the UH3 phase will provide images of all the hemodynamic parameters with high spatial and temporal resolution. This work will result in a new approach for functional brain imaging and demonstrative results that will motivate adoption by others and future advancements towards wearable devices at a reduced cost.