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Proceedings Paper

High-resolution endoscopic optical coherence tomography of airways (Conference Presentation)

Paper Abstract

Diagnosis of peripheral lung nodules through transbronchial biopsy is highly prone to sampling errors due to the inability of current techniques to accurately locate and/or sample lesions. Volumetric optical imaging techniques such as optical coherence tomography (OCT) have the potential to address this issue, however, current imaging catheter designs cannot achieve sufficiently high-resolution, or diffraction-limited imaging; focusing elements bear spherical aberrations and multilayered structures with asymmetric curvatures in the optical path cause astigmatism. In this work, we propose a new class of optical imaging catheters – termed nano-optic endoscope – that use metalenses to achieve diffraction-limited endoscopic imaging at greatly extended depth-of-focus through negating non-chromatic aberrations and chromatic dispersion engineering. A metalens consists of a 2-dimentional array of subwavelength-spaced scatterers with specific geometric parameters and distribution that locally shift the phase of the incident light and modify its wavefront. The metalens ability to arbitrarily and accurately modify the phase allows the nano-optic endoscope to overcome spherical aberrations and astigmatism. Remarkably, the tailored chromatic dispersion of the metalens in the context of spectral interferometry is utilized to maintain high-resolution imaging beyond the input field Rayleigh range, overcoming the compromise between transverse resolution and depth-of-focus. Endoscopic imaging is demonstrated ex vivo in resected human airway specimens and in vivo in sheep airways. Fine pathology such as irregular glandular pattern, the hallmark of adenocarcinoma, is readily visualized in high-resolution images captured by the nano-optic endoscope. The versatility and design flexibility of the nano-optic endoscope significantly elevate endoscopic imaging capabilities that will likely impact clinical applications.

Paper Details

Date Published: 4 March 2019
Proc. SPIE 10854, Endoscopic Microscopy XIV, 108540T (4 March 2019); doi: 10.1117/12.2510524
Show Author Affiliations
Hamid Pahlevaninezhad, Harvard Medical School (United States)
Massachusetts General Hospital (United States)
Mohammadreza Khorasaninejad, Harvard Univ. (United States)
Yao-Wei Huang, Harvard Univ. (United States)
Zhujun Shi, Harvard Univ. (United States)
Lida P. Hariri, Harvard Univ. (United States)
David C. Adams, Massachusetts General Hospital (United States)
Harvard Medical School (United States)
Cheng-Wei Qiu, National Univ. of Singapore (Singapore)
Federico Capasso, Harvard Univ. (United States)
Melissa J. Suter, Massachusetts General Hospital (United States)
Harvard Medical School (United States)

Published in SPIE Proceedings Vol. 10854:
Endoscopic Microscopy XIV
Guillermo J. Tearney M.D.; Thomas D. Wang; Melissa J. Suter, Editor(s)

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