Amending of fluorescence sensor signal localization in human skin by matching of the refractive index

Abstract

Fluorescence diagnostic techniques are notable amongst many other optical methods because they offer high sensitivity and noninvasive measurement of tissue properties. However, a combination of multiple scattering and physical heterogeneity of biological tissues hampers interpretation of the fluorescence measurements. Analyses of the spatial distribution of endogenous and exogenous fluorophores excitation within tissues and their contribution to the detected signal localization are essential for many applications. We have developed a novel Monte Carlo technique that gives a graphical perception of how the excitation and fluorescence detected signal are localized in tissues. Our model takes into account the spatial distribution of fluorophores, the variation of concentrations and quantum yield. We demonstrate that matching the refractive indices of the ambient medium and topical skin layer improves spatial localization of the detected fluorescence signal within the tissues.

Peer-to-peer Monte Carlo simulation of photon migration in topical applications of biomedical optics

“…1 An opportunity to imitate directly the influence of varieties of structural and physiologic properties of biological tissues on the photon migration for a particular source-detector configuration makes MC a primary tool in biomedical optics and optical engineering. A number of MC codes have been developed in the past [1][2][3][4][5] and applied extensively for various biomedical applications, including light dosimetry modelling for photodynamic therapy treatment planning, 6 simulation of reflectance spectra of human skin, 7 analysis of fluorescence excitation in skin tissues, 8 imitation of photon migration in the brain, 9 two-dimensional images of skin by optical coherence tomography (OCT), 10 and others. It has been demonstrated that MC technique is able to provide a broad variety of practical solutions in a range of biomedical studies from single cells to the biopsy of specific biological tissues and whole organs.…”

Numerical feasibility analysis of an epidermal glucose sensor based on time-resolved fluorescence

“…Several studies have reported the steady-state intensity and spatial distribution of fluorescence emission from hypothetical sensors under the skin using the Monte Carlo method [2,3,39]. In the present study, simulations of time-resolved fluorescence from sensors embedded between the epidermis and the papillary dermis are presented for the first time.…”

Using peer-to-peer network for on-line Monte Carlo computation of fluence rate distribution

“…An opportunity to imitate directly the influence of varieties of structural and physiological properties of biological tissues on the photon migration for a particular source-detector configuration makes MC a primary tool in biomedical optics and optical engineering. A number of advanced online MC applications have been developed in the past 1 and applied extensively for various biomedical applications, including light dosimeter modeling for photodynamic therapy treatment planning 2 , simulation of reflectance spectra of human skin 3,4 , analysis of fluorescence excitation in skin tissues [5][6][7] , simulation of photon migration in human brain 8 , imitation of optical coherence tomography (OCT) images of human skin [9][10][11] and other [12][13][14][15] . It has been demonstrated that MC technique is able to provide a broad variety of practical solutions in a range of biomedical studies from single cells to the biopsy of specific biological tissues and whole organs.…”