Development of non-contact rheometry for measuring rheological properties of biological fluids

摘要/总结 背景：生物体液的流变特性与生物体液的各种生理特性密切相关 流程.例如，血液粘度障碍与血液流变学的进展显著相关。 冠心病、外周动脉疾病、中风和高粘血症。表面张力 粘液的分泌受肺部病理过程的影响。虽然流体的流变性质是 作为诊断和评估疾病进展的重要生物标志物， 主要用于工业应用。现有的基于旋转和基于管的流变仪 装置不能同时测量流体的表面张力和粘度。另外存在 当前用于测量粘度的流变仪和测量方法的各种缺点 表面张力，例如需要接触样品，需要高度熟练的操作员和清洁 每个样品之间的测试室。 该项目旨在通过开发非接触式流变仪来解决这些未满足的关键需求 使用小体积样品（薄的， 层流体）。 方法：我们将利用超声波作为激励源或“声学压头”， 毛细管波的流体表面上，并使用光学相干断层扫描（OCT）作为测量 精确记录波动中质点位移的装置。通过这种实验方法，样品 在培养皿中的样品绝不会与测量仪器的任何部分直接接触。我们之前的工作 利用毛细波在深流体制度，以测量表面张力和粘度。我们将以此为基础 以前的工作，以扩大理论模型到薄层流体的情况下，毛细波在浅层流体 以类似的非接触方式。我们将优化所提出的流变学方法，以实现 高精度和高精度的薄层测量。 为实现本项目的目标，我们提出以下具体目标： ·目的1）构建并验证浅层流变特性理论模型 液体情况。 ·目标2）优化流变测量采集方法和信号处理以产生稳健的结果 在薄的流体层中。 影响：所提出的技术将进行测量，具有以下优点，包括 非接触式、全自动、快速，测试之间不需要清洁，这提供了一种生物友好的 环境

ABSTRACT/SUMMARY Background: Rheological properties of biological fluids are closely linked with various physiological processes. For example, disorders of blood viscosity are significantly associated with the progression of coronary heart disease, peripheral artery diseases, stroke and hyperviscosity syndromes. The surface tension of mucus is influenced by pathological processes in the lungs. While rheological properties of fluids are important biomarkers critical to diagnose and evaluate progression of diseases, rheometry instruments have been primarily developed for industrial applications. Existing rotational-based and tube-based rheometry devices are not capable of measuring both surface tension and viscosity of fluids. Additionally, there are various drawbacks of current rheometry instruments for measuring viscosity and methods for measuring surface tension such as the need for contacting samples, necessitating highly skilled operators, and cleaning the testing chamber between each sample. This project aims to address these unmet and critical needs by developing a non-contact rheometry method for measuring biological fluid surface tension and viscosity using small volume samples (thin- layer fluid). Methods: We will utilize ultrasound as an excitation source or “acoustic indenter” to generate a propagating capillary wave on the surface of the fluid and use optical coherence tomography (OCT) as a measurement device to precisely record particle displacements of wave motion. With this experimental approach, the sample in a Petri dish is never in direct contact with any part of the measurement apparatus. Our previous work has utilized capillary waves in a deep fluid regime to measure surface tension and viscosity. We will build on this previous work to extend the theoretical model into the thin-layer fluid case, capillary waves in a shallow fluid regime, in a similar non-contact fashion. We will optimize the proposed rheometry method to achieve measurements with high accuracy and precision for thin-layer measurements. To accomplish the goals of this project we propose these Specific Aims: • Aim 1) Construct and validate the theoretical model for rheological properties in the shallow fluid case. • Aim 2) Optimize the rheometry acquisition method and signal processing to yield robust results in thin fluid layers. Impact: The proposed technique will carry out measurements with the following advantages including being non-contact, fully automated, fast, and not needing cleaning between tests, which provides a biology-friendly environment.