Evidence map›Paper›PMID 40621165›Full record

ArticleJournal of biomedical optics2025

Flexible catheter optical coherence tomography of the porcine middle ear via the Eustachian tube using a 3D-printed reflective objective.

Clayton B Walker, Kevin Beckford, Zihan Yang, Jinyun Liu, Wihan Kim, Tomasz S Tkaczyk, Brian E Applegate

Abstract read
In one paragraph

Article in Journal of biomedical optics, 2025. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 5 papers.

0numbers the graph read from it
0cells of the map it votes in
5citing papers in PubMed
–field-weighted citation impact
1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.

Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

5 citing papers in PubMed.

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4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

7 authors.

Clayton B WalkerUniversity of Southern California, Caruso Department of Otolaryngology - Head and Neck Surgery, Los Angeles, California, United States.ORCID 0000-0003-1137-9071
Kevin BeckfordRice University, Department of Electrical Engineering, Houston, Texas, United States.ORCID 0009-0007-2110-0376
Zihan YangUniversity of Southern California, Caruso Department of Otolaryngology - Head and Neck Surgery, Los Angeles, California, United States.ORCID 0000-0003-1409-4725
Jinyun LiuRice University, Department of Bioengineering, Houston, Texas, United States.ORCID 0009-0009-7962-4513
Wihan KimUniversity of Southern California, Caruso Department of Otolaryngology - Head and Neck Surgery, Los Angeles, California, United States.ORCID 0000-0002-4448-7215
Tomasz S TkaczykRice University, Department of Electrical Engineering, Houston, Texas, United States.
Brian E ApplegateUniversity of Southern California, Caruso Department of Otolaryngology - Head and Neck Surgery, Los Angeles, California, United States.

Funding

Optical imaging technologies to identify residual cholesteatoma and improve ossiculoplasty outcomesR01EB027113 · NIBIB · UNIVERSITY OF SOUTHERN CALIFORNIA · PI APPLEGATE, BRIAN E. · 2019 to 2022
$2.6M
OCT imaging of the human inner earR01DC022232 · NIDCD · UNIVERSITY OF SOUTHERN CALIFORNIA · PI John S Oghalai · 2025 to 2026
$1.4M
NIBIB NIH HHS R01 EB027113NIDCD NIH HHS R01 DC022232
6 · The paper itself

Abstract

Significance: Cholesteatomas, benign tumors that grow in the middle ear, can lead to conductive hearing loss. If not completely removed during surgery, these tumors may regrow. Current imaging technologies struggle to detect residual tumors noninvasively due to limitations in contrast and resolution, often necessitating additional surgery for inspection. To address this, we developed a catheter endoscope capable of being inserted through the Eustachian tube, allowing detailed examination of the middle ear without surgery. Using two-photon polymerization (2PP) technology, we fabricated miniature, side-viewing reflective endoscope objectives. This approach enabled the rapid production of single-element objectives with highly repeatable optical properties, easily adaptable to specific imaging needs. Aim: We aim to design, fabricate, and demonstrate a catheter endoscope for optical coherence tomography (OCT) endoscopy of the middle ear via the Eustachian tube. Approach: Side-viewing, reflective lenses were designed in OpticStudio and 3D printed using 2PP followed by sputter coating with gold. Standard metrology techniques were used to verify and optimize the objective's shape. The optical performance of the catheter endoscopes was measured with a beam profiler. Finally, OCT imaging of the middle ear of a pig via the Eustachian tube was completed using the fully assembled catheter endoscope. Results: Metrology showed the printed lenses conformed closely to the design. The catheter endoscope's FWHM spot size had a mean ± standard deviation of Conclusions: The 2PP approach is fast and highly repeatable for miniature reflective objective fabrication. OCT catheter endoscopy via the Eustachian tube enabled imaging of the middle ear, Eustachian tube, and surprisingly part of the inner ear.

Indexed as

Ear, MiddleEustachian TubePrinting, Three-DimensionalTomography, Optical CoherenceAnimalsCathetersEndoscopyEquipment DesignSwineadditive manufacturingcatheter endoscopeoptical coherence tomographytwo-photon polymerization

Identifiers

PMID40621165
PMCPMC12223792

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Registered trials

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Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.