In vivo time-domain diffuse correlation spectroscopy above the water absorption peak

2020 ◽  
Vol 45 (13) ◽  
pp. 3377
Author(s):  
L. Colombo ◽  
M. Pagliazzi ◽  
S. Konugolu Venkata Sekar ◽  
D. Contini ◽  
T. Durduran ◽  
...  
Keyword(s):  
Water Absorption ◽  
Time Domain ◽  
Correlation Spectroscopy ◽  
Absorption Peak ◽  
Diffuse Correlation Spectroscopy

scholarly journals Time-domain diffuse correlation spectroscopy (TD-DCS) for noninvasive, depth-dependent blood flow quantification in human tissue in vivo

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Saeed Samaei ◽  
Piotr Sawosz ◽  
Michał Kacprzak ◽  
Żanna Pastuszak ◽  
Dawid Borycki ◽  
...  
Keyword(s):  
Blood Flow ◽  
Time Domain ◽  
Human Tissue ◽  
Correlation Spectroscopy ◽  
Flow Quantification ◽  
Flow Index ◽  
Flow Measurements ◽  
Diffuse Correlation Spectroscopy ◽  
Sensing Applications

AbstractMonitoring of human tissue hemodynamics is invaluable in clinics as the proper blood flow regulates cellular-level metabolism. Time-domain diffuse correlation spectroscopy (TD-DCS) enables noninvasive blood flow measurements by analyzing temporal intensity fluctuations of the scattered light. With time-of-flight (TOF) resolution, TD-DCS should decompose the blood flow at different sample depths. For example, in the human head, it allows us to distinguish blood flows in the scalp, skull, or cortex. However, the tissues are typically polydisperse. So photons with a similar TOF can be scattered from structures that move at different speeds. Here, we introduce a novel approach that takes this problem into account and allows us to quantify the TOF-resolved blood flow of human tissue accurately. We apply this approach to monitor the blood flow index in the human forearm in vivo during the cuff occlusion challenge. We detect depth-dependent reactive hyperemia. Finally, we applied a controllable pressure to the human forehead in vivo to demonstrate that our approach can separate superficial from the deep blood flow. Our results can be beneficial for neuroimaging sensing applications that require short interoptode separation.

scholarly journals Time domain diffuse correlation spectroscopy with a high coherence pulsed source: in vivo and phantom results

2017 ◽  
Vol 8 (11) ◽  
pp. 5311 ◽  
Author(s):  
M. Pagliazzi ◽  
S. Konugolu Venkata Sekar ◽  
L. Colombo ◽  
E. Martinenghi ◽  
J. Minnema ◽  
...  
Keyword(s):  
Time Domain ◽  
Correlation Spectroscopy ◽  
Diffuse Correlation Spectroscopy ◽  
High Coherence

In vivo time-domain diffuse correlation spectroscopy at 1 μm

2021 ◽  
Author(s):  
Lorenzo Colombo ◽  
Marco Pagliazzi ◽  
Sanathana Konugolu Venkata Sekar ◽  
Davide Contini ◽  
Turgut Durduran ◽  
...  
Keyword(s):  
Time Domain ◽  
Correlation Spectroscopy ◽  
Diffuse Correlation Spectroscopy

In vivo time-domain diffuse correlation spectroscopy of the human muscle above 1000 nm

2019 ◽  
Author(s):  
Lorenzo Colombo ◽  
M. Pagliazzi ◽  
Sanathana Konugolu Venkata Sekar ◽  
Davide Contini ◽  
Alberto Dalla Mora ◽  
...  
Keyword(s):  
Time Domain ◽  
Human Muscle ◽  
Correlation Spectroscopy ◽  
Diffuse Correlation Spectroscopy

scholarly journals Diffuse Correlation Spectroscopy at Short Source-Detector Separations: Simulations, Experiments and Theoretical Modeling

2019 ◽  
Vol 9 (15) ◽  
pp. 3047 ◽  
Author(s):  
Karthik Vishwanath ◽  
Sara Zanfardino
Keyword(s):  
Diffusion Theory ◽  
Small Animal ◽  
Tissue Perfusion ◽  
Flow Channel ◽  
Correlation Spectroscopy ◽  
Diffuse Correlation Spectroscopy ◽  
Non Invasive ◽  
Yield Information ◽  
Theoretical Analyses

Diffuse correlation spectroscopy (DCS) has widely been used as a non-invasive optical technique to measure tissue perfusion in vivo. DCS measurements are quantified to yield information about moving scatterers using photon diffusion theory and are therefore obtained at long source-detector separations (SDS). However, short SDS DCS could be used for measuring perfusion in small animal models or endoscopically in clinical studies. Here, we investigate the errors in analytically retrieved flow coefficients from simulated and experimental data acquired at short SDS. Monte Carlo (MC) simulations of photon correlation transport was programmed to simulate DCS measurements and used to (a) examine the accuracy and validity of theoretical analyses, and (b) model experimental measurements made on phantoms at short SDS. Experiments consisted of measurements from a series of optical phantoms containing an embedded flow channel. Both the fluid flow rate and depth of the flow channel from the liquid surface were varied. Inputs to MC simulations required to model experiments were obtained from corrected theoretical analyses. Results show that the widely used theoretical DCS model is robust for quantifying relative changes in flow. We also show that retrieved flow coefficients at short SDS can be scaled to retrieve absolute values via MC simulations.

scholarly journals Portable System for Time-Domain Diffuse Correlation Spectroscopy

2019 ◽  
Vol 66 (11) ◽  
pp. 3014-3025 ◽  
Author(s):  
Davide Tamborini ◽  
Kimberly A. Stephens ◽  
Melissa M. Wu ◽  
Parya Farzam ◽  
Andrew M. Siegel ◽  
...  
Keyword(s):  
Time Domain ◽  
Correlation Spectroscopy ◽  
Diffuse Correlation Spectroscopy ◽  
Portable System
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