Novel dual-channel configuration of non-contact diffuse reflectance spectroscopy towards assessing the spectral absorption at a depth below 1mm

Nafiseh Farahzadi; Daqing Piao; Ranjith Ramanathan

doi:10.1117/12.3001559

12 March 2024 Novel dual-channel configuration of non-contact diffuse reflectance spectroscopy towards assessing the spectral absorption at a depth below 1mm

Nafiseh Farahzadi, Daqing Piao, Ranjith Ramanathan

Author Affiliations +

Proceedings Volume 12836, Optical Biopsy XXII: Toward Real-Time Spectroscopic Imaging and Diagnosis; 1283608 (2024) https://doi.org/10.1117/12.3001559
Event: SPIE BiOS, 2024, San Francisco, California, United States

Abstract

It is challenging to assess the spectral absorption of sub-surface medium using non-contact diffuse reflectance spectroscopy (DRS). A demanding application of such is assessing myoglobin oxygenation at a depth of >1mm to inform beef discoloration. Common to the broad-band DRS and especially challenging to non-contact DRS conducted in continuous-wave, probing the sub-surface medium needs to deal with several geometry-dictated limitations in the measurements. For example, photons of longer pathlength are to be acquired to probe the deeper medium. However, the information associated with the photons with paths specific to only the sub-surface layer of the deep-probing path cannot be easily isolated in the measurement when additional information specific to only the shallower layer is absent. Another challenge to instrumentation relates to the substantially different scales of the magnitudes of the shallower probing and deeper probing DRS signals when originating from the same source of illumination at a similar timeframe. We demonstrate a novel dual-channel non-contact DRS for the assessment of spectral absorption at a depth of below 1mm. The dual-channel non-contact DRS combines a center-illuminated-central- acquired (CIC-A) geometry and a center-illuminated-central-blocked (CIC-B) geometry that are co-centric with respect to the same point-of-illumination (POI). The CIC-A geometry enables probing the surface layer of less than 1mm deep. And the CIC-B geometry acquires deep-probing photons while rejecting the short-path-shallow-probing- only components that would confound otherwise. The combination of CIC-A and CIC-B geometries allows assessing the below-surface spectral absorption. The principle is demonstrated by measurements from phantoms and tissues conforming to a two-layer geometry.

Conference Presentation

(2024) Published by SPIE. Downloading of the abstract is permitted for personal use only.

Citation Download Citation

Nafiseh Farahzadi, Daqing Piao, and Ranjith Ramanathan "Novel dual-channel configuration of non-contact diffuse reflectance spectroscopy towards assessing the spectral absorption at a depth below 1mm", Proc. SPIE 12836, Optical Biopsy XXII: Toward Real-Time Spectroscopic Imaging and Diagnosis, 1283608 (12 March 2024); https://doi.org/10.1117/12.3001559

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