Nematic liquid crystal spatial light modulator for mimicking laser speckle contrast imaging

摘要

Laser speckle contrast imaging (LSCI) is a non- or minimally- invasive modality for observing relative blood flow or perfusion. Recently, there has been an effort to use LSCI for truly quantitative blood flow measurements. However, this effort has been hampered not only by real theoretical issues, but also by challenges associated with numerous experimental parameters that can potentially impact the calculated contrast values. In this work, we present our efforts at using a nematic liquid crystal, phase-only, spatial light modulator (SLM) to mimic LSCI experiments with precisely controlled experimental parameters. This approach permits the rapid experimental investigation of numerous factors including: The effects of different flow models on LSCI contrast values; the effects of multiple decorrelation times in the same depth of field; the effects of 'static' scatterers; and the effects of camera settings relative to speckle decorrelation times, just to name a few. We have found that an SLM is a useful tool for the experimental investigation of LSCI that eliminates many of the experimental variables associated with typical flow model experiments or in vivo experimentation. LSCI experiments with SLMs are a useful intermediary between computer simulations and physical flow models.