Quantification of path-length-resolved blood flow changes of human tissue by time-domain diffuse correlation spectroscopy (TD-DCS)

Author(s):  
Saeed Samaei ◽  
Piotr Sawosz ◽  
Michal Kacprzak ◽  
Dawid Borycki ◽  
Adam Liebert
2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Saeed Samaei ◽  
Piotr Sawosz ◽  
Michał Kacprzak ◽  
Żanna Pastuszak ◽  
Dawid Borycki ◽  
...  

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.


Author(s):  
Songfeng Han ◽  
Hyun Jin Kim ◽  
Ki Won Jung ◽  
Halley F. Tsai ◽  
Ashley R. Proctor ◽  
...  

2021 ◽  
Vol 8 (03) ◽  
Author(s):  
Dibbyan Mazumder ◽  
Melissa M. Wu ◽  
Nisan Ozana ◽  
Davide Tamborini ◽  
Maria Angela Franceschini ◽  
...  

2020 ◽  
Author(s):  
Chien-Sing Poon ◽  
Feixiao Long ◽  
Ulas Sunar

ABSTRACTDiffuse correlation spectroscopy (DCS) is increasingly used in the optical imaging field to assess blood flow in humans due to its non-invasive, real-time characteristics and its ability to provide label-free, bedside monitoring of blood flow changes. Previous DCS studies have utilized a traditional curve fitting of the analytical or Monte Carlo models to extract the blood flow changes, which are computationally demanding and less accurate when the signal to noise ratio decreases. Here, we present a deep learning model that eliminates this bottleneck by solving the inverse problem more than 2300% faster, with equivalent or improved accuracy compared to the nonlinear fitting with an analytical method. The proposed deep learning inverse model will enable real-time and accurate tissue blood flow quantification with the DCS technique.


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