Real-time absorption and scattering characterization of slab-shaped turbid samples obtained by a combination of angular and spatially resolved measurements

Abstract

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Measurements of optical properties of pig brain tissue in vitro using a novel compact device

“…The absorption varied more, probably due to the small sampling volume, leading to low sensitivity to absorption in a medium with a relatively low absorption coefficient. The evaluated new technique is interesting due to the advantages it has over IS method: the sample does not have to be moved during the measurements, no bulky spheres are needed, and there is the possibility of sampling smaller volumes 19 .…”

Deducing effective light transport parameters in optically thin systems

“…Taking advantage of the large set of simulations performed, we developed a look-up table (LUT) routine to demonstrate the capabilities of a combined mean square width/decay time approach. In the literature, several LUT approaches have been proposed, based on both experimental [44] and simulated data [43,45,[67][68][69][70][71][72]. In contrast with a standard fit, look-up table routines rely on single scalar parameters directly linked to transport properties, such as, typically, the total amount of transmitted/ballistic/reflected light from a slab.…”

“…In contrast with a standard fit, look-up table routines rely on single scalar parameters directly linked to transport properties, such as, typically, the total amount of transmitted/ballistic/reflected light from a slab. This triplet of observables, often referred to as T tot , T coll and R tot , has been extensively exploited to retrieve optical parameters through Monte Carlo-LUT routines [43,45,[67][68][69][70][71][72], despite the fact that such absolute intensity measurements are extremely challenging [43,70] and prone to unpredictable systematic errors [72]. Moreover, while the natural propensity of Monte Carlo-based data evaluation techniques is towards the study of optically thin media, integrated transmittance/reflectance quantities do actually loose their usefulness as the sample thickness decreases [11], since the acquired signal will be eventually dominated by light that has been either specularly reflected or ballistically transmitted through the sample, thus carrying almost no information about its properties.…”

In vitro measurements of optical properties of porcine brain using a novel compact device

“…W e thus believe that we can neglect the effect of an assumed error in the g-factor used in the training set in the present study. The evaluated new technique is interesting owing to the advantages it has over the IS method: the sample does not have to be moved during the measurements, no bulky spheres are needed, and there is the possibility of sampling smaller volumes (DAM et al, 2005). As configured here, the CASH sensor obtains data at one wavelength only, whereas the IS system records full spectral information.…”

“…To circumvent some of these problems, we have developed a novel system for measuring the optical properties of tissue, presented by DAM et al (2005). This system is constructed to enable real-time, simultaneous determination of /x,, /xs, and g from thin turbid samples using a continuous wave (i.e.…”