Feature Of The Week 2/12/12: Researchers at Yale University use OCT to Characterize Microfluidic Ciliary Induced Fluid Flow
Recently researchers at Yale University demonstrated a very novel application of optical coherence tomography using a Thorlabs OCT system. The research involved characterizing microfluidic flow of fluid driven by cilia. Below is a summary of this interesting and novel application of OCT.
Motile cilia are fingerlike projections from different epithelial surfaces that move in a periodic manner to generate directional fluid flow. For example, respiratory cilia generate a microfluidic-scale flow that moves pathogen and allergen-containing mucus out of the lungs. Defects in motile cilia lead to recurrent respiratory infections. Despite the importance of cilia in rare disease such as primary ciliary dyskinesia and their possible role in more common disease such as asthma, there are no routine methods for characterizing the flow performance of a ciliated surface. We therefore have investigated the use of optical coherence tomography (OCT) to quantify cilia-driven fluid flow. Since traditional Doppler OCT is not well-suited to measure flow along a surface that is orthogonal to the optical axis, we used particle tracking velocimetry to measure two-dimensional, two-component flow fields generated by a ciliated surface. For our experiments, we used a popular animal model in ciliary biology- Xenopus embryos. Amphibian embryos including frogs in the Xenopus genus have ciliated skin that generates direction fluid flow. Xenopus embryo skin also shares important features with ciliated respiratory epithelium: both have multiciliated cells, and both have mucous-secreting cells. Our results show that OCT has tremendous potential for imaging cilia-driven fluid. OCT-based particle tracking velocimetry is able to quantify complex flow profiles, yielding two-dimensional, two-component flow vector maps. We also demonstrated that biological cilia can drive recirculatory flow patterns consistent with microfluidic mixing. Our ongoing work is focused on translating these findings into mouse models of respiratory disease and into a clinical diagnostic test.
For more information see resent Article. Courtesy Michael Choma from Yale University.