Neurophotonics Center, Department of Biomedical Engineering, Boston University, Boston, MA, USA.
Reality Labs Research, Meta Platforms Inc, Menlo Park, CA, USA.
Commun Biol. 2023 Aug 14;6(1):844. doi: 10.1038/s42003-023-05211-4.
Cerebral blood flow (CBF) is crucial for brain health. Speckle contrast optical spectroscopy (SCOS) is a technique that has been recently developed to measure CBF, but the use of SCOS to measure human brain function at large source-detector separations with comparable or greater sensitivity to cerebral rather than extracerebral blood flow has not been demonstrated. We describe a fiber-based SCOS system capable of measuring human brain activation induced CBF changes at 33 mm source detector separations using CMOS detectors. The system implements a pulsing strategy to improve the photon flux and uses a data processing pipeline to improve measurement accuracy. We show that SCOS outperforms the current leading optical modality for measuring CBF, i.e. diffuse correlation spectroscopy (DCS), achieving more than 10x SNR improvement at a similar financial cost. Fiber-based SCOS provides an alternative approach to functional neuroimaging for cognitive neuroscience and health science applications.
脑血流 (CBF) 对大脑健康至关重要。散斑对比光光谱学 (SCOS) 是一种最近开发的测量 CBF 的技术，但尚未证明 SCOS 可用于在与大脑血流相比具有可比或更高灵敏度的大源-探测器分离距离下测量人类大脑功能。我们描述了一种基于光纤的 SCOS 系统，该系统能够使用 CMOS 探测器在 33mm 的源-探测器分离距离处测量人类大脑激活引起的 CBF 变化。该系统实施了一种脉冲策略来提高光子通量，并使用数据处理管道来提高测量精度。我们表明，SCOS 的性能优于当前用于测量 CBF 的领先光学模式，即漫反射相关光谱 (DCS)，在类似的财务成本下，SNR 提高了 10 倍以上。基于光纤的 SCOS 为认知神经科学和健康科学应用提供了一种替代功能神经影像学的方法。
