Stray light mitigation in a novel endoscope for fallopian tubes

Elizabeth Swan; Tyler Tate; Molly Keenan; John F. Black; Urs Utzinger; Jennifer Barton

doi:10.1117/12.2078671

2 March 2015 Stray light mitigation in a novel endoscope for fallopian tubes

Elizabeth Swan, Tyler Tate, Molly Keenan, John F. Black, Urs Utzinger, Jennifer Barton

Proceedings Volume 9304, Endoscopic Microscopy X; and Optical Techniques in Pulmonary Medicine II; 93041O (2015) https://doi.org/10.1117/12.2078671
Event: SPIE BiOS, 2015, San Francisco, California, United States

Abstract

Stray light in an endoscope largely contributes to whether a signal can be detected or not. This FRED analysis used a novel endoscope designed for the fallopian tubes to show how common endoscope elements cause stray light contamination, and to offer suggestions on how to mitigate it. Standard and advanced optical raytracing was performed. Raytrace reports determined which ray paths caused the highest power and irradiance distributions after reflecting one or more times from an element in the system. The analysis revealed that the cover plate introduced significantly more stray light into the system than other endoscope components. The imaging lenses and variable stop reflectivity had a negligible impact on the signal. To obtain acceptable signal-to- noise ratio, the source numerical aperture (NA) was lowered to 0.35 and 0.25 to keep the stray light within the same order of magnitude and an order of magnitude lower, respectively than the desired signal. There was a single specular reflection off of the cover plate distal surface. This illumination reflected back into the imaging fiber without first scattering off the tissue, which resulted in high stray power at the back of the imaging lenses. The specular light appeared brighter at higher source NAs and saturated the desired signal at the edge of the imaging fiber. An NA between 0.25 and 0.35 provides maximum illumination to image the tissue, with minimal stray light degrading the desired signal.

Citation Download Citation

Elizabeth Swan, Tyler Tate, Molly Keenan, John F. Black, Urs Utzinger, and Jennifer Barton "Stray light mitigation in a novel endoscope for fallopian tubes", Proc. SPIE 9304, Endoscopic Microscopy X; and Optical Techniques in Pulmonary Medicine II, 93041O (2 March 2015); https://doi.org/10.1117/12.2078671

ACCESS THE FULL ARTICLE

INSTITUTIONAL
Select your institution to access the SPIE Digital Library.

SELECT YOUR INSTITUTION

PERSONAL
Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.

PERSONAL SIGN IN

No SPIE Account? Create one

PURCHASE THIS CONTENT

SUBSCRIBE TO DIGITAL LIBRARY

50 downloads per 1-year subscription

Members: $195

Non-members: $335 ADD TO CART

25 downloads per 1 - year subscription

Members: $145

Non-members: $250 ADD TO CART

PURCHASE SINGLE ARTICLE

Includes PDF, HTML & Video, when available