Study the effects of varying interference upon the optical properties of turbid samples using NIR spatial light modulation

Shaul, Oren; Fanrazi-Kahana, Michal; Meitav, Omri; Pinhasi, Gad A.; Abookasis, David

doi:10.1016/j.optcom.2017.10.067

Cited by 4 publications

(1 citation statement)

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“…In this single occlusion measurement, differences in both coefficient values are shown and highlight the changes in tissue hemodynamic parameters and structure. The pressure applied by the rubber deforms the geometry of the tissue and causes distortion of its internal structure, chromophore distribution, and blood flow, thereby altering the diffuse light reflectance which is a function of absorption and scattering properties [63][64][65][66]. The increases in absorption coefficient correspond primarily to the accumulation of deoxyhemoglobin during the occlusion, and the decrease in scattering primarily to the changes in cell density and presumably edema evolution.…”

Section: Study #2: Vascular Occlusionmentioning

confidence: 99%

Multiparameter wide‐field integrated optical imaging system‐based spatially modulated illumination and laser speckles in model of tissue injuries

Bloygrund

Franjy-Tal

Rosenzweig

et al. 2019

Journal of Biophotonics

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In this report, an integrated optical platform based on spatial illumination together with laser speckle contrast technique was utilized to measure multiple parameters in live tissue including absorption, scattering, saturation, composition, metabolism, and blood flow. Measurements in three models of tissue injury including drug toxicity, artery occlusion, and acute hyperglycemia were used to test the efficacy of this system. With this hybrid apparatus, a series of structured light patterns at low and high spatial frequencies are projected onto the tissue surface and diffuse reflected light is captured by a CCD camera. A six position filter wheel, equipped with four bandpass filters centered at wavelengths of 650, 690, 800 and 880 nm is placed in front of the camera. Then, light patterns are blocked and a laser source at 650 nm illuminates the tissue while the diffusely reflected light is captured by the camera through the two remaining open holes in the wheel. In this manner, near‐infrared (NIR) and laser speckle images are captured and stored together in the computer for off‐line processing to reconstruct the tissue's properties. Spatial patterns are used to differentiate the effects of tissue scattering from those of absorption, allowing accurate quantification of tissue hemodynamics and morphology, while a coherent light source is used to study blood flow changes, a feature which cannot be measured with the NIR structured light. This combined configuration utilizes the strengths of each system in a complementary way, thus collecting a larger range of sample properties. In addition, once the flow and hemodynamics are measured, tissue oxygen metabolism can be calculated, a property which cannot be measured independently. Therefore, this merged platform can be considered a multiparameter wide‐field imaging and spectroscopy modality. Overall, experiments demonstrate the capability of this spatially coregistered imaging setup to provide complementary, useful information of various tissue metrics in a simple and noncontact manner, making it attractive for use in a variety of biomedical applications.

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Section: Study #2: Vascular Occlusionmentioning

confidence: 99%