Ciliated epithelial cells populate up to 80% of the surface area of the human airway and are responsible for
mucociliary transport, which is the key protective mechanism that provides the first line of defense in the respiratory
tract. Cilia beat in a rhythmic pattern and may be easily affected by allergens, pollutants, and pathogens, altering ciliary
beat frequency (CBF) subsequently. Diseases including cystic fibrosis, chronic obstructive pulmonary disease, and
primary ciliary dyskinesia may also decrease CBF. CBF is therefore a critical component of respiratory health. The
current clinical method of measuring CBF is phase-contrast microscopy, which involves a tissue biopsy obtained via
brushing of the nasal cavity. While this method is minimally invasive, the tissue sample must be oriented to display its
profile view, making the visualization of a single layer of cilia challenging. In addition, the conventional method
requires subjective analysis of CBF, e.g., manually counting by visual inspection. On the contrary, optical coherence
tomography (OCT) has been used to study the retina in ophthalmology as well as vasculature in cardiology, and offers
higher resolution than conventional computed tomography and magnetic resonance imaging. Based on this technology,
our lab specifically developed an ultra-high resolution OCT system to image the microstructure of the ciliated epithelial
cells. Doppler analysis was also performed to determine CBF. Lastly, we also developed a program that utilizes fast
Fourier transform to determine CBF under phase-contrast microscopy, providing a more objective method compared to
the current method.
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