Significance: Imaging biofluid flow under physiologic conditions aids in understanding disease processes and health complications. We present a method employing a microparallel plate strain induction chamber (MPPSIC) amenable to optical coherence tomography to track depth-resolved lateral displacement in fluids in real time while under constant and sinusoidal shear. Aim: Our objective is to track biofluid motion under shearing conditions found in the respiratory epithelium, first validating methods in Newtonian fluids and subsequently assessing the capability of motion-tracking in bronchial mucus. Approach: The motion of polystyrene microspheres in aqueous glycerol is tracked under constant and sinusoidal applied shear rates in the MPPSIC and is compared with theory. Then 1.5 wt. % bronchial mucus samples considered to be in a normal hydrated state are studied under sinusoidal shear rates of amplitudes 0.7 to 3.2 s − 1. Results: Newtonian fluids under low Reynolds conditions (Re ∼ 10 − 4) exhibit velocity decreases directly proportional to the distance from the plate driven at both constant and oscillating velocities, consistent with Navier–Stokes’s first and second problems at finite depths. A 1.5 wt. % mucus sample also exhibits a uniform shear strain profile. Conclusions: The MPPSIC provides a new capability for studying biofluids, such as mucus, to assess potentially non-linear or strain-rate-dependent properties in a regime that is relevant to the mucus layer in the lung epithelium.

中文翻译：

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微平行板应变诱导室中生物流体的 OCT 粒子跟踪测速

意义：在生理条件下对生物流体流动进行成像有助于了解疾病过程和健康并发症。我们提出了一种采用微平行板应变感应室 (MPPSIC) 的方法，该方法适用于光学相干断层扫描，以在恒定和正弦剪切下实时跟踪流体中的深度分辨横向位移。目的：我们的目标是在呼吸上皮中发现的剪切条件下跟踪生物流体运动，首先验证牛顿流体中的方法，然后评估支气管粘液中运动跟踪的能力。方法：在 MPPSIC 中在恒定和正弦应用剪切速率下跟踪聚苯乙烯微球在含水甘油中的运动，并与理论进行比较。然后 1.5 重量。在振幅为 0.7 至 3.2 s - 1 的正弦剪切速率下研究被认为处于正常水合状态的支气管粘液百分比。 结果：低雷诺条件下的牛顿流体 (Re ∼ 10 - 4) 表现出速度下降与距离成正比来自以恒定速度和振荡速度驱动的板块，这与 Navier-Stokes 在有限深度的第一和第二个问题一致。1.5 重量。% 粘液样品也表现出均匀的剪切应变曲线。结论：MPPSIC 为研究生物流体（如粘液）提供了一种新能力，可在与肺上皮粘液层相关的机制中评估潜在的非线性或应变率依赖性。牛顿流体在低雷诺数条件下 (Re ∼ 10 - 4) 表现出的速度下降与以恒定速度和振荡速度驱动的板块的距离成正比，这与 Navier-Stokes 在有限深度的第一和第二个问题一致。1.5 重量。% 粘液样品也表现出均匀的剪切应变曲线。结论：MPPSIC 为研究生物流体（如粘液）提供了一种新能力，可在与肺上皮粘液层相关的机制中评估潜在的非线性或应变率依赖性。牛顿流体在低雷诺数条件下 (Re ∼ 10 - 4) 表现出的速度下降与以恒定速度和振荡速度驱动的板块的距离成正比，这与 Navier-Stokes 在有限深度的第一和第二个问题一致。1.5 重量。% 粘液样品也表现出均匀的剪切应变曲线。结论：MPPSIC 为研究生物流体（如粘液）提供了一种新能力，可在与肺上皮粘液层相关的机制中评估潜在的非线性或应变率依赖性。