Abstract
Quantitative endoscopic imaging is at the vanguard of novel techniques in the assessment upper airway obstruction.
Anatomic optical coherence tomography (aOCT) has the potential to provide the geometry of the airway lumen with
high-resolution and in 4 dimensions. By coupling aOCT with measurements of pressure, optical coherence
elastography (OCE) can be performed to characterize airway wall stiffness. This can aid in identifying regions of
dynamic collapse as well as informing computational fluid dynamics modeling to aid in surgical decision-making.
Toward this end, here we report on an anatomic optical coherence tomography (aOCT) system powered by a
wavelength-swept laser source. The system employs a fiber-optic catheter with outer diameter of 0.82 mm deployed
via the bore of a commercial, flexible bronchoscope. Helical scans are performed to measure the airway geometry and
to quantify the cross-sectional-area (CSA) of the airway. We report on a preliminary validation of aOCT for
elastography, in which aOCT-derived CSA was obtained as a function of pressure to estimate airway wall compliance.
Experiments performed on a Latex rubber tube resulted in a compliance measurement of 0.68±0.02 mm2/cmH2O, with
R2=0.98 over the pressure range from 10 to 40 cmH2O. Next, ex vivo porcine trachea was studied, resulting in a
measured compliance from 1.06±0.12 to 3.34±0.44 mm2/cmH2O, (R2>0.81). The linearity of the data confirms the
elastic nature of the airway. The compliance values are within the same order-of-magnitude as previous measurements
of human upper airways, suggesting that this system is capable of assessing airway wall compliance in future human
studies.
