Sensitivity analysis for oblique incidence reflectometry using Monte Carlo simulations

Kamran, Faisal; Andersen, Peter E.

doi:10.1364/ao.54.007099

Cited by 7 publications

(4 citation statements)

References 29 publications

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“…For best use of resources, an optical sensor should be implemented to determine the composition of milk in every step from the farmers’ raw milk to the bottling of homogenized ultra-high temperature (UHT) milk without dilution or separation of a sample and without the need for calibration. Recently, a lot of effort was put into investigating commercial or homogenized milk using different methods, using hyperspectral imaging, 1 laser light scattering, 2,3 oblique incidence reflectometry, 4 spatially resolved diffuse reflectance spectroscopy, 5,6 transmission mode spectroscopy, 7 photon time-of-flight spectroscopy, 8 or using diluted milk samples in an angular resolved setup. 9 All these techniques showed correlations of the fat content and the scattering properties of milk.…”

Section: Introductionmentioning

confidence: 99%

Broadband Optical Properties of Milk

et al. 2016

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Dairy products play an important role in our daily nutrition. As a turbid scattering medium with different kinds of particles and droplets, each alteration of these components changes the scattering properties of milk. The goal of this work is the determination of the amount of main scattering components, the fat droplets and the casein micelles, by understanding the light propagation in homogenized milk and in raw milk. To provide the absolute impact of these milk components, the geometrical and optical properties such as the size distribution and the refractive index (RI) of the components have to be examined. We determined the reduced scattering coefficient [Formula: see text] and the absorption coefficient [Formula: see text] from integrating sphere measurements. By use of a collimated transmission setup, the scattering coefficient [Formula: see text] was measured. Size measurements were performed to validate the influence of the fat droplet size on the results of the scattering properties; also, the RI of both components was determined by the said coefficients. These results were used to determine the absolute impact of the milk components on the scattering behavior. By fitting Mie theory calculations on scattering spectra [Formula: see text] and [Formula: see text] from different raw milk samples, it was possible to get reliable values for the concentrations of fat and casein and for the size of the fat droplets. By destroying the casein micelles, it was possible to separate the influence of the different scattering components on scattering behavior.

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Section: Introductionmentioning

confidence: 99%

Broadband Optical Properties of Milk

et al. 2016

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“…In recent years, milk has often been measured by different diffuse reflectance measurements; 31–35 the idea of an oblique illumination has already partly been applied. 36 Our setup differs from these measurements since it is more sensitive to changes in the scattering phase function and the anisotropy factor. The advantage of the lateral transmission setup over the oblique incident reflectometry is the independence over surface roughness.…”

Section: Resultsmentioning

confidence: 99%

Spatially Resolved Lateral Transmission Measurements to Characterize Changes in the Scattering Coefficient and the Anisotropy Factor

2018

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A new setup is described to characterize the scattering coefficient and the scattering phase function of liquid media. The setup utilizes the basic idea of a spatially resolved reflectance measurement combined with a sophisticated illumination geometry. The sample is illuminated parallel and close to the interface of the sample and a glass window to get information from single scattered and multiple scattered light. By illuminating the sample with a fiber orientated with the axis parallel to the glass surface, small distances to the source can be examined unimpeded by the illumination beam. The derived information is, for example, not only sensitive to the concentration of the scatterers but also to the size of the scattering particles. We present the setup including the theory to describe the light propagation in the whole configuration using Monte Carlo simulations. The validation has been done with polystyrene microsphere dispersions with different scattering coefficients. As application for the developed setup, we show measurements of different milk samples which vary in concentration of fat, protein, and in fat droplet size during homogenization process. By measuring milk, we show the ability of the sensor to determine information about the scattering phase function without diluting the sample. For sensors in the dairy industry, a measurement with no pre-processing and no diluting of the sample is worthwhile, because this can be used to determine the fat and protein concentration on-line.

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“…Note that Intralipid perfusion is purely Brownian when v = 0 mms −1 . Also, reduced scattering coefficients of Teflon and 9% Intralipid were measured to be 35 cm −1 and 25 cm −1 [15,28], respectively, using oblique incidence reflectometry [21,22].…”

Section: Tissue Phantomsmentioning

confidence: 99%

“…Unlike the system devised by Sadhwani et al and other instruments for diffuse reflectance laser speckle detection using scientific-or industrial-grade cameras [15][16][17][18], our apparatus takes advantage of advancements of miniature-camera technology in biomedical sciences [11,13,14,19,20] and employs a camera-phone for diffuse reflectance speckle detection. While the basic setup used here is similar to that of oblique incidence reflectometry (OIR) [21,22], we analyze spatial intensity variations in diffuse reflectance laser speckle patterns rather than OIR distances between the diffusion center and illumination entry point. Note that a technique related to ours, termed diffuse correlation spectroscopy, based on temporal autocorrelation analysis of rapidly fluctuating photon count signals from a single speckle was used to assess burn severity in vivo in a porcine burn model using fiber optics and photon-counting photomultiplier tubes [23].…”

Section: Introductionmentioning

confidence: 99%

In vivo burn diagnosis by camera-phone diffuse reflectance laser speckle detection

Ragol¹,

Remer²,

Shoham³

et al. 2015

Biomed. Opt. Express

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Burn diagnosis using laser speckle light typically employs widefield illumination of the burn region to produce two-dimensional speckle patterns from light backscattered from the entire irradiated tissue volume. Analysis of speckle contrast in these time-integrated patterns can then provide information on burn severity. Here, by contrast, we use point illumination to generate diffuse reflectance laser speckle patterns of the burn. By examining spatiotemporal fluctuations in these time-integrated patterns along the radial direction from the incident point beam, we show the ability to distinguish partial-thickness burns in a porcine model in vivo within the first 24 hours post-burn. Furthermore, our findings suggest that time-integrated diffuse reflectance laser speckle can be useful for monitoring burn healing over time post-burn. Unlike conventional diffuse reflectance laser speckle detection systems that utilize scientific or industrial-grade cameras, our system is designed with a camera-phone, demonstrating the potential for burn diagnosis with a simple imager.

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Sensitivity analysis for oblique incidence reflectometry using Monte Carlo simulations

Cited by 7 publications

References 29 publications

Broadband Optical Properties of Milk

Broadband Optical Properties of Milk

Spatially Resolved Lateral Transmission Measurements to Characterize Changes in the Scattering Coefficient and the Anisotropy Factor

In vivo burn diagnosis by camera-phone diffuse reflectance laser speckle detection

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