Related Experiment Video
Updated: Sep 11, 2025
Real-Time Monitoring of Neurocritical Patients with Diffuse Optical Spectroscopies
Published on: November 19, 2020
Comparison of diffuse correlation spectroscopy, interferometric diffusing wave spectroscopy, and speckle contrast
Joseph B Majeski1, Rodrigo M Forti1,2, Sang Hoon Chong1,3
1University of Pennsylvania, Department of Physics and Astronomy, Philadelphia, Pennsylvania, United States.
Significance:
Noninvasive optical measurements of blood flow have many applications. Measurements have been demonstrated with diffuse correlation spectroscopy (DCS), interferometric diffusing wave spectroscopy (iDWS), and speckle contrast optical spectroscopy (SCOS) techniques, but concurrent measurements with all three techniques in the same experiment have not been compared.
Aim:
We aim to evaluate the comparative strengths and weaknesses of SCOS, iDWS, and DCS methods in controlled experiments.
Approach:
We performed in vitro temperature-controlled microsphere flow phantom and in vivo arm cuff occlusion experiments using SCOS, iDWS, and DCS concurrently and in the same geometry.
Results:
In vitro results showed absolute flow metrics agreement between iDWS and DCS and demonstrated large gains in signal-to-noise for iDWS and SCOS compared with DCS; relative changes in flow measured by SCOS were also in good agreement with DCS and iDWS. The in vivo cuff occlusion results showed agreement of relative changes in flow measured by DCS, iDWS, and SCOS. However, DCS recovered a flow pulsatility index that was larger than iDWS and SCOS indices.
Conclusions:
The experiments demonstrate the equivalency of absolute flow measures from iDWS and DCS and improved precision of pulsatile waveforms from SCOS. These results emphasize the need for rapid development and adoption of iDWS and SCOS.
