Quantitative, depth-resolved determination of particle motion using multi-exposure, spatial frequency domain laser...

Area of Science:

• Biomedical Optics
• Medical Imaging
• Photonics

Background:

• Laser Speckle Imaging (LSI) offers noninvasive particle motion imaging in scattering media.
• Current LSI provides only qualitative blood flow indices due to confounding variables.
• Quantitative, depth-resolved LSI is needed for accurate biological tissue analysis.

Purpose of the Study:

• To develop and validate a quantitative, depth-resolved LSI method.
• To account for variables affecting speckle contrast in LSI.
• To enable accurate reconstruction of flow dynamics and speeds in biological tissues.

Main Methods:

• Combined Monte Carlo modeling, multi-exposure speckle imaging (MESI), and spatial frequency domain imaging (SFDI).
• Utilized controlled phantom experiments with structured light.
• Explored multi-layer geometries including diffusive and directed flow.

Main Results:

• Accurately reconstructed particle flow type (diffusive/directed) in each layer.
• Precisely determined layer thickness and absolute flow speeds.
• Achieved flow speed accuracy within 15% or better.

Conclusions:

• The developed method enables quantitative, depth-resolved LSI.
• This approach overcomes limitations of traditional qualitative LSI.
• Validated method shows potential for precise blood flow quantification in biological tissues.