Spatially resolved, single-ended two-dimensional visualization of gas flow phenomena using structured illumination

Kristensson, Elias; Richter, Mattias; Pettersson, Sven-Göran; Aldén, Marcus; Andersson‐Engels, Stefan

doi:10.1364/ao.47.003927

Cited by 17 publications

(4 citation statements)

References 11 publications

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“…16 Since this report, many works have been published through the years, using structured illumination as a sectioning tool for different biomedical microscopy applications. [17][18][19][20][21][22][23][24][25] In 1998, Dögnitz and Wagni showed for the first time the ability of spatially modulated illumination to separately obtain the optical properties from phantoms and human skin in a noncontact manner. 26 A few years later in 2005, Cuccia et al extended this technique and presented its capability to perform both diffuse optical tomography (depth sectioning) and wide-field quantitative mapping of tissue optical properties in the NIR region.…”

Section: Introductionmentioning

confidence: 99%

Closed head injury-induced changes in brain pathophysiology assessed with near-infrared structured illumination in a mouse model

2013

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Use of near-infrared (NIR) structured illumination technique has recently received great interest in biomedical research and clinical studies because of its ability to perform wide-field imaging and quantitatively map changes in tissue hemodynamic properties and morphological features in a noncontact and scan-free fashion. We report on the feasibility of using the same to quantitatively monitor and map changes in brain optical properties and physiological parameters pre- and post-closed head injury in a mouse model. Five anesthetized male mice underwent head injury by weight-drop model using a ~50-g cylindrical metal object falling from a height of 90 cm onto the intact scalp. During experiments, NIR structured illumination was projected on the mouse head at two spatial frequencies and six different NIR wavelengths. A CCD camera positioned perpendicular to the head recorded the diffuse-reflected light. Computer analysis performed off-line on the captured data reveals spatiotemporal changes in the distribution of brain tissue absorption and reduced scattering coefficients. Using Beer's law and Mie theory, hemodynamic (hemoglobin, oxygen saturation, and lipids) and morphological (scattering amplitude and power) changes up to 1-h post-trauma were observed in comparison with baseline measurements. Functional maps of different brain properties were also generated. Following injury, we found difference in both brain hemodynamic and morphologic properties with respect to baseline levels, where in some properties, this difference was considered statistically significant. Specifically, a t-test indicates a substantial decrease in oxyhemoglobin (HbO(2)) concentration and tissue oxygen saturation (StO(2)) post-injury (p < 0.01 and p < 0.001, respectively). Overall, our preliminary results demonstrate the potential application of NIR structured illumination technique to track and spatially map changes in intact mouse brain pathophysiological parameters following head injury.

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Section: Introductionmentioning

confidence: 99%

Closed head injury-induced changes in brain pathophysiology assessed with near-infrared structured illumination in a mouse model

2013

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“…Cortizo et al used a structured light source to study the topography of the sole of the foot during a walk [7] while Kristensson et. al implemented the technique for the study of a dynamic flow of water droplets [8].…”

Section: Introductionmentioning

confidence: 99%

Analysis of multiple scattering suppression using structured laser illumination planar imaging in scattering and fluorescing media

Kristensson¹,

Araneo²,

Berrocal³

et al. 2011

Opt. Express

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The accuracy, precision and limitations of the imaging technique named Structured Laser Illumination Planar Imaging (SLIPI) have been investigated. SLIPI, which allows multiply scattered light to be diminished, has previously demonstrated improvements in image quality and contrast for spray imaging. In the current study the method is applied to a controlled confined environment consisting of a mixture of water and monodisperse polystyrene microspheres. Elastic scattering and fluorescence are studied and the results obtained when probing different particle concentrations and diameters conclusively show the advantages of SLIPI for imaging within moderately turbid media. Although the technique presents both good repeatability and agreement with the Beer-Lambert law, discrepancies in its performance were, however, discovered. Photons undergoing scattering without changing their incident trajectory cannot be discriminated and, owing to differences in scattering phase functions, probing larger particles reduces the suppression of multiply scattered light. However, in terms of visibility such behavior is beneficial as it allows denser media to be probed. It is further demonstrated that the suppression of diffuse light performs equally well regardless of whether photons propagate along the incident direction or towards the camera. In addition, this filtering process acts independently on the spatial distribution of the multiply scattered light but is limited by the finite dynamic range and unavoidable signal noise of the camera

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“…This process works as directional filter and extract most of the unique diffusion of photons in the propagation direction, considerably improving the contrast of the image [18]. Note that the principle of this technique is entirely well described in the literature [19] [20] [21] [22], particularly in Chapter 6 of Kristensson PhD Thesis (see Ref. [18]).…”

Section: Principle Of Slipi Techniquementioning

confidence: 99%

Structured Imagery Processing Strategies for Spectroscopic Measurement in Dense Solutions

Koffi¹,

Regnima²,

Bosson³

et al. 2017

OJAppS

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Absorbance measurement in dense media via conventional optical spectroscopy techniques leads to inaccurate results. This is mainly due to multiple scattering phenomena that contribute to the overall light extinction in the interrogated sample. This limitation imposes the use of dilute solutions for absorption spectroscopy. However, depending on the polarity of the solvent used, the absorption spectrum may vary over a given solution. Structured illumination technique offers an alternative to this problem, and provides the ability to calculate in-situ optical properties in dense media. In this paper, we propose two processing methods applied to images acquired by structured laser illumination planar imaging (SLIPI) technique to extract extinction coefficients µ of probed solutions: The first is based on the implementation of principal component analysis (PCA) and the second, on the calculation of Mean Value. In practice, two kinds of studies were carried out: one quantitative set of measurements within chlorophyll liquid solutions and a second set with concentrated coffee solutions, with controlled proportion and concentrations for each sample. These two proposed analytical techniques are advantageous because they are very easy to implement and provide a much simpler alternative to the previous one. Both methods offer satisfactory results, similar to those obtained with the original method which is based on 1D Fourier transform.

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Spatially resolved, single-ended two-dimensional visualization of gas flow phenomena using structured illumination

Cited by 17 publications

References 11 publications

Closed head injury-induced changes in brain pathophysiology assessed with near-infrared structured illumination in a mouse model

Closed head injury-induced changes in brain pathophysiology assessed with near-infrared structured illumination in a mouse model

Analysis of multiple scattering suppression using structured laser illumination planar imaging in scattering and fluorescing media

Structured Imagery Processing Strategies for Spectroscopic Measurement in Dense Solutions

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