We present a new approach to Diffuse Correlation Spectroscopy (DCS) which overcomes the limited light throughput of single mode photon counting techniques, and operates with continuous wave illumination without disturbance from ambient light. Heterodyne holographic detection allows parallel measurement of the power spectrum of a fluctuating electric field across thousands of modes, from which we may directly compute flow parameters using a novel Fourier domain DCS model. Our detection and modelling strategy are rigorously validated by modulating the Brownian and flow components of an optical tissue phantom, demonstrating absolute measurements of the Brownian diffusion coefficient in excellent agreement with conventional methods. We demonstrate the feasability of in vivo measurement through the recovery of pulsatile flow rates measured in the human forearm.

Date Published: 21 February 2020
PDF: 7 pages
Proc. SPIE 11239, Dynamics and Fluctuations in Biomedical Photonics XVII, 112390H (21 February 2020); doi: 10.1117/12.2545177

Published in SPIE Proceedings Vol. 11239:
Dynamics and Fluctuations in Biomedical Photonics XVII
Valery V. Tuchin; Martin J. Leahy; Ruikang K. Wang, Editor(s)