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Fourier domain diffuse correlation spectroscopy with heterodyne holographic detection

We present a new approach to diffuse correlation spectroscopy which overcomes the limited light throughput of single-mode photon counting techniques. Our system employs heterodyne holographic detection to allow parallel measurement of the power spectrum of a fluctuating electric field across thousan...

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Detalles Bibliográficos
Autores principales: James, Edward, Powell, Samuel
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Optical Society of America 2020
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7687971/
https://www.ncbi.nlm.nih.gov/pubmed/33282522
http://dx.doi.org/10.1364/BOE.400525
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author James, Edward
Powell, Samuel
author_facet James, Edward
Powell, Samuel
author_sort James, Edward
collection PubMed
description We present a new approach to diffuse correlation spectroscopy which overcomes the limited light throughput of single-mode photon counting techniques. Our system employs heterodyne holographic detection to allow parallel measurement of the power spectrum of a fluctuating electric field across thousands of modes, at the shot noise limit, using a conventional sCMOS camera. This yields an order of magnitude reduction in detector cost compared to conventional techniques, whilst also providing robustness to the effects of ambient light and an improved signal-to-noise ratio during in vitro experiments. We demonstrate a GPU-accelerated holographic demodulation system capable of processing the incoming data (79.4 M pixels per second) in real-time, and a novel Fourier domain model of diffuse correlation spectroscopy which permits the direct recovery of flow parameters from the measured data. Our detection and modelling strategy are rigorously validated by modulating the Brownian component of an optical tissue phantom, demonstrating absolute measurements of the Brownian diffusion coefficient in excellent agreement with conventional methods. We further demonstrate the feasibility of our system through in vivo measurement of pulsatile flow rates measured in the human forearm.
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spelling pubmed-76879712020-12-03 Fourier domain diffuse correlation spectroscopy with heterodyne holographic detection James, Edward Powell, Samuel Biomed Opt Express Article We present a new approach to diffuse correlation spectroscopy which overcomes the limited light throughput of single-mode photon counting techniques. Our system employs heterodyne holographic detection to allow parallel measurement of the power spectrum of a fluctuating electric field across thousands of modes, at the shot noise limit, using a conventional sCMOS camera. This yields an order of magnitude reduction in detector cost compared to conventional techniques, whilst also providing robustness to the effects of ambient light and an improved signal-to-noise ratio during in vitro experiments. We demonstrate a GPU-accelerated holographic demodulation system capable of processing the incoming data (79.4 M pixels per second) in real-time, and a novel Fourier domain model of diffuse correlation spectroscopy which permits the direct recovery of flow parameters from the measured data. Our detection and modelling strategy are rigorously validated by modulating the Brownian component of an optical tissue phantom, demonstrating absolute measurements of the Brownian diffusion coefficient in excellent agreement with conventional methods. We further demonstrate the feasibility of our system through in vivo measurement of pulsatile flow rates measured in the human forearm. Optical Society of America 2020-10-28 /pmc/articles/PMC7687971/ /pubmed/33282522 http://dx.doi.org/10.1364/BOE.400525 Text en Published by The Optical Society under the terms of the Creative Commons Attribution 4.0 License. Further distribution of this work must maintain attribution to the author(s) and the published article’s title, journal citation, and DOI. Published by The Optical Society under the terms of the Creative Commons Attribution 4.0 License (http://creativecommons.org/licenses/by/4.0/) . Further distribution of this work must maintain attribution to the author(s) and the published article’s title, journal citation, and DOI.
spellingShingle Article
James, Edward
Powell, Samuel
Fourier domain diffuse correlation spectroscopy with heterodyne holographic detection
title Fourier domain diffuse correlation spectroscopy with heterodyne holographic detection
title_full Fourier domain diffuse correlation spectroscopy with heterodyne holographic detection
title_fullStr Fourier domain diffuse correlation spectroscopy with heterodyne holographic detection
title_full_unstemmed Fourier domain diffuse correlation spectroscopy with heterodyne holographic detection
title_short Fourier domain diffuse correlation spectroscopy with heterodyne holographic detection
title_sort fourier domain diffuse correlation spectroscopy with heterodyne holographic detection
topic Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7687971/
https://www.ncbi.nlm.nih.gov/pubmed/33282522
http://dx.doi.org/10.1364/BOE.400525
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