Quantitative modeling of laser speckle imaging

TL;DR

This paper investigates how scattering affects laser speckle imaging (LSI) and introduces a refined processing scheme to accurately estimate relaxation time despite scattering-induced distortions.

Contribution

The study combines experimental and simulation approaches to analyze scattering effects in LSI and proposes a new processing method for better relaxation time estimation.

Findings

Scattering significantly impacts spatial resolution and signal quality in LSI.

Multiple scattering causes blurring of dynamic inhomogeneities.

A refined processing scheme improves relaxation time estimation in scattering environments.

Abstract

We have analyzed the image formation and dynamic properties in laser speckle imaging (LSI) both experimentally and with Monte-Carlo simulation. We show for the case of a liquid inclusion that the spatial resolution and the signal itself are both significantly affected by scattering from the turbid environment. Multiple scattering leads to blurring of the dynamic inhomogeneity as detected by LSI. The presence of a non-fluctuating component of scattered light results in the significant increase in the measured image contrast and complicates the estimation of the relaxation time. We present a refined processing scheme that allows a correct estimation of the relaxation time from LSI data.