Continuous and longitudinal monitoring of cerebral blood flow (CBF) in animal models provides information for studying the mechanisms and interventions of various cerebral diseases. Since anesthesia may affect brain hemodynamics, researchers have been seeking wearable devices for use in conscious animals. We present a wearable diffuse speckle contrast flowmeter (DSCF) probe for monitoring CBF variations in mice. The DSCF probe consists of a small low-power near-infrared laser diode as a point source and an ultrasmall low-power CMOS camera as a two-dimensional detector array, which can be affixed on a mouse head. The movement of red blood cells in brain cortex (i.e., CBF) produces spatial fluctuations of laser speckles, which are captured by the camera. The DSCF system was calibrated using tissue phantoms and validated in a human forearm and mouse brains for continuous monitoring of blood flow increases and decreases against the established technologies. Significant correlations were observed among these measurements ($\text{R}^{2}\geq \,{\text{0.80}}$ , $\text{p} < {\text{10}}^{- \text{5}}$). This small fiberless probe has the potential to be worn by a freely moving conscious mouse. Moreover, the flexible source–detector configuration allows for varied probing depths up to ${\sim\text{8 mm}}$, which is sufficient for transcranially detecting CBF in the cortices of rodents and newborn infants.

中文翻译：

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一种用于连续监测小鼠脑血流的可穿戴无光纤光学传感器

对动物模型中脑血流 (CBF) 的连续和纵向监测为研究各种脑疾病的机制和干预措施提供了信息。由于麻醉可能会影响脑血流动力学，研究人员一直在寻找用于有意识的动物的可穿戴设备。我们提出了一种可穿戴的漫斑对比流量计 (DSCF) 探头，用于监测小鼠的 CBF 变化。DSCF探头由作为点光源的小型低功率近红外激光二极管和作为二维探测器阵列的超小型低功率CMOS相机组成，可固定在鼠标头部。大脑皮层（即CBF）中红细胞的运动会产生激光散斑的空间波动，并被相机捕捉到。DSCF 系统使用组织模型进行校准，并在人类前臂和小鼠大脑中进行了验证，以根据既定技术连续监测血流量的增加和减少。在这些测量值之间观察到显着的相关性（$\text{R}^{2}\geq \,{\text{0.80}}$ , $\text{p} < {\text{10}}^{- \text{5}}$）。这种小型无纤维探头有可能被自由移动的有意识的老鼠佩戴。此外，灵活的源探测器配置允许不同的探测深度，最高可达 ${\sim\text{8 毫米}}$，这足以经颅检测啮齿动物和新生儿皮质中的 CBF。