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Fig. 1: A DSCFO System. (a) User interface ① and DSCFO device ②. (b) Components for DSCFO device including customized circuit to drive laser diodes ③, Raspberry Pi controller ④, camera electronic (AC62KUSB) ⑤, DSCFO probe ⑥, NanEye camera ⑦, and laser diodes ⑧. (c) A schematic of DSCFO. (d) A wearable probe glued on the skull.
Diffuse Speckle Contrast Flow-Oximetry (DSCFO). Supported by the NIH, we have developed an innovative, low-cost, fiber-free, wearable diffuse speckle contrast flow-oximetry (DSCFO) probe with varied dimensions/sizes, which affixes to heads of animals (mice, rats, piglets) and human newborns for continuous cerebral blood flow (CBF) and cerebral blood oxygen saturation (StO2) monitoring during naturally behavioral conditions. DSCFO uses small laser diodes at different near-infrared wavelengths as point sources for noninvasive deep tissue penetration (up to ~10 mm depth) and a tiny CMOS camera as a high-density 2D detector array to detect spatial diffuse laser speckle fluctuations, resulting from movement of red blood cells in the brain (i.e., CBF). Alternative measurements of light intensity attenuations at different wavelengths enable quantification of StO2 using near-infrared spectroscopy principle. Importantly, connections between the wearable DSCFO probe and a portable device are all flexible electrical wires (i.e., fiber-free), allowing for continuous cerebral monitoring in freely behaving subjects.
