Igor Meglinski | University of Oulu (original) (raw)

Papers by Igor Meglinski

Complex Dynamics and Fluctuations in Biomedical Photonics III, 2006

ABSTRACT

Saratov Fall Meeting 2011: Optical Technologies in Biophysics and Medicine XIII, 2012

ABSTRACT An increasingly popular area of interest in biomedical diagnostics is the high sensitivi... more ABSTRACT An increasingly popular area of interest in biomedical diagnostics is the high sensitivity of scattered polarized light to subtle alterations in tissue morphology. Insight in to these interactions has lead to the development of real time non-invasive diagnostic and therapy methods, and will continue to do so, improving both the detection of diseases, and treatment responses in early stages. Here, the fundamental properties of circular polarized light, and its application to observe morphologic changes in biological tissues has been studied. The optical properties of biological tissues have been altered with the use of optical clearing agents and the polarization state of their scattered light analyzed. Following these observations, research into the feasibility of distinguishing changes in optical parameters of the media has been carried out. The results showed that using the specific polarimetry system, alterations to the phantom medium and biological tissues were resolvable, furthermore a particular dependence on the anisotropy of the scattering medium was found. This method provides a good foundation for future work implementing non-invasive diagnostic techniques for early disease detection, as many forms of cancerous growths alter the scattering anisotropy of the affected tissue.

Handbook of Coherent-Domain Optical Methods, 2012

ABSTRACT This chapter describes the application of diffusing wave spectroscopy (DWS) for noninvas... more ABSTRACT This chapter describes the application of diffusing wave spectroscopy (DWS) for noninvasive characterization of skin blood flow and skin blood microcirculation in vivo. The DWS is a simple but ingenious approach, utilizing the loss of correlation of scattered laser light to observe the structural changes and displacement of scattering particles, such as red blood cells (RBC) within the biological tissues. This approach has the potential to be so specific that it can revolutionize the currently developed techniques for blood flow monitoring. Developments in DWS are likely to lead it to be used for characterization of skin blood microcirculation, to assess burn depth, to diagnose atherosclerotic disease, and investigate mechanisms of photodynamic therapy for cancer treatment, as well as to monitor pharmacological intervention for failing surgical skin flaps or replants.

Asia Communications and Photonics Conference 2014, 2014

Journal of Biomedical Optics

Fluorescence diagnostic techniques are notable amongst many other optical methods because they of... more 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.

Quantum Electronics

A review of studies on the numerical simulation of coherent effects in random media performed by ... more A review of studies on the numerical simulation of coherent effects in random media performed by using exact analytic results is presented. The simulation procedure is based on a comparison of the Monte-Carlo method and the iteration solution of the Bethe ë Salpeter equation. The results of calculations of the time correlation function and the interference component of coherent backscattering for scalar and electromagnetic éelds are described. The simulation results are compared for the érst time with known generalisations of the Milne solution and are in good agreement with experimental data. The interference component of backscattered low-coherent radiation is calculated for the érst time. The localisation of backscattered low-coherent laser radiation along the penetration depth is described. The theory and numerical simulation predict, in accordance with the experiment, a considerable broadening of the backscattering peak with decreasing the coherence length, which opens up essentially new possibilities for the use of this effect, especially for medical diagnostics.

Quantum Electronics

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Proceedings of SPIE - The International Society for Optical Engineering

We study coherent and non-coherent backscattering of circularly polarized light from turbid media... more We study coherent and non-coherent backscattering of circularly polarized light from turbid media. We find that the sign of helicity of circular polarized light does not change for a medium of point-like scatterers and can change significantly for the medium with high anisotropy of scatterers. The helicity flip is observed when the light scattering is described in terms of the Henyey-Greenstein scattering phase function. The angular dependence of the sum of coherent and non-coherent parts of backscattering also exhibits a helicity flip.

Progress In Electromagnetics Research M

To describe propagation of polarized electromagnetic wave within a disperse random medium a new M... more To describe propagation of polarized electromagnetic wave within a disperse random medium a new Monte Carlo based technique with an adopted vector formalism has been developed. The technique has been applied for simulation of coherent backscattering of circularly polarized optical radiation from a random scattering medium. It has been found that the sign of helicity of circular polarized light does not change for a medium of point-like scatterers and can change significantly for the scatterers with the higher anisotropy. We conclude that the helicity flip of the circular polarized light can be observed in the tissue-like media. We find that this phenomenon manifests itself in case of limited number of scattering events and, apparently, can be attributed to the pulse character of incident radiation rather than to the specific form of scattering particles.

Biophotonics 2007: Optics in Life Science, 2007

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Quantum Electronics, 2014

Optical Tomography, Photon Migration, and Spectroscopy of Tissue and Model Media: Theory, Human Studies, and Instrumentation, 1995

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ICONO '98: Laser Spectroscopy and Optical Diagnostics: Novel Trends and Applications in Laser Chemistry, Biophysics, and Biomedicine, 1999

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Optical Biopsy and Fluorescence Spectroscopy and Imaging, 1995

ABSTRACT

Physical review. E, Statistical, nonlinear, and soft matter physics, 2015

We investigate the survival of circularly polarized light in random scattering media. The surpris... more We investigate the survival of circularly polarized light in random scattering media. The surprising persistence of this form of polarization has a known dependence on the size and refractive index of scattering particles, however a general description regarding polydisperse media is lacking. Through analysis of Mie theory, we present a means of calculating the magnitude of circular polarization memory in complex media, with total generality in the distribution of particle sizes and refractive indices. Quantification of this memory effect enables an alternate pathway toward recovering particle size distribution, based on measurements of diffusing circularly polarized light.

Diagnostic Optical Spectroscopy in Biomedicine II, 2003

ABSTRACT

Saratov Fall Meeting 2010: Optical Technologies in Biophysics and Medicine XII, 2010

ABSTRACT

5th International Conference on Laser Applications in Life Sciences, 1995

ABSTRACT

Complex Dynamics and Fluctuations in Biomedical Photonics III, 2006

ABSTRACT

Saratov Fall Meeting 2011: Optical Technologies in Biophysics and Medicine XIII, 2012

ABSTRACT An increasingly popular area of interest in biomedical diagnostics is the high sensitivi... more ABSTRACT An increasingly popular area of interest in biomedical diagnostics is the high sensitivity of scattered polarized light to subtle alterations in tissue morphology. Insight in to these interactions has lead to the development of real time non-invasive diagnostic and therapy methods, and will continue to do so, improving both the detection of diseases, and treatment responses in early stages. Here, the fundamental properties of circular polarized light, and its application to observe morphologic changes in biological tissues has been studied. The optical properties of biological tissues have been altered with the use of optical clearing agents and the polarization state of their scattered light analyzed. Following these observations, research into the feasibility of distinguishing changes in optical parameters of the media has been carried out. The results showed that using the specific polarimetry system, alterations to the phantom medium and biological tissues were resolvable, furthermore a particular dependence on the anisotropy of the scattering medium was found. This method provides a good foundation for future work implementing non-invasive diagnostic techniques for early disease detection, as many forms of cancerous growths alter the scattering anisotropy of the affected tissue.

Handbook of Coherent-Domain Optical Methods, 2012

ABSTRACT This chapter describes the application of diffusing wave spectroscopy (DWS) for noninvas... more ABSTRACT This chapter describes the application of diffusing wave spectroscopy (DWS) for noninvasive characterization of skin blood flow and skin blood microcirculation in vivo. The DWS is a simple but ingenious approach, utilizing the loss of correlation of scattered laser light to observe the structural changes and displacement of scattering particles, such as red blood cells (RBC) within the biological tissues. This approach has the potential to be so specific that it can revolutionize the currently developed techniques for blood flow monitoring. Developments in DWS are likely to lead it to be used for characterization of skin blood microcirculation, to assess burn depth, to diagnose atherosclerotic disease, and investigate mechanisms of photodynamic therapy for cancer treatment, as well as to monitor pharmacological intervention for failing surgical skin flaps or replants.

Asia Communications and Photonics Conference 2014, 2014

Journal of Biomedical Optics

Fluorescence diagnostic techniques are notable amongst many other optical methods because they of... more 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.

Quantum Electronics

A review of studies on the numerical simulation of coherent effects in random media performed by ... more A review of studies on the numerical simulation of coherent effects in random media performed by using exact analytic results is presented. The simulation procedure is based on a comparison of the Monte-Carlo method and the iteration solution of the Bethe ë Salpeter equation. The results of calculations of the time correlation function and the interference component of coherent backscattering for scalar and electromagnetic éelds are described. The simulation results are compared for the érst time with known generalisations of the Milne solution and are in good agreement with experimental data. The interference component of backscattered low-coherent radiation is calculated for the érst time. The localisation of backscattered low-coherent laser radiation along the penetration depth is described. The theory and numerical simulation predict, in accordance with the experiment, a considerable broadening of the backscattering peak with decreasing the coherence length, which opens up essentially new possibilities for the use of this effect, especially for medical diagnostics.

Quantum Electronics

ABSTRACT

Proceedings of SPIE - The International Society for Optical Engineering

We study coherent and non-coherent backscattering of circularly polarized light from turbid media... more We study coherent and non-coherent backscattering of circularly polarized light from turbid media. We find that the sign of helicity of circular polarized light does not change for a medium of point-like scatterers and can change significantly for the medium with high anisotropy of scatterers. The helicity flip is observed when the light scattering is described in terms of the Henyey-Greenstein scattering phase function. The angular dependence of the sum of coherent and non-coherent parts of backscattering also exhibits a helicity flip.

Progress In Electromagnetics Research M

To describe propagation of polarized electromagnetic wave within a disperse random medium a new M... more To describe propagation of polarized electromagnetic wave within a disperse random medium a new Monte Carlo based technique with an adopted vector formalism has been developed. The technique has been applied for simulation of coherent backscattering of circularly polarized optical radiation from a random scattering medium. It has been found that the sign of helicity of circular polarized light does not change for a medium of point-like scatterers and can change significantly for the scatterers with the higher anisotropy. We conclude that the helicity flip of the circular polarized light can be observed in the tissue-like media. We find that this phenomenon manifests itself in case of limited number of scattering events and, apparently, can be attributed to the pulse character of incident radiation rather than to the specific form of scattering particles.

Biophotonics 2007: Optics in Life Science, 2007

ABSTRACT

Quantum Electronics, 2014

Optical Tomography, Photon Migration, and Spectroscopy of Tissue and Model Media: Theory, Human Studies, and Instrumentation, 1995

ABSTRACT

ICONO '98: Laser Spectroscopy and Optical Diagnostics: Novel Trends and Applications in Laser Chemistry, Biophysics, and Biomedicine, 1999

ABSTRACT

Optical Biopsy and Fluorescence Spectroscopy and Imaging, 1995

ABSTRACT

Physical review. E, Statistical, nonlinear, and soft matter physics, 2015

We investigate the survival of circularly polarized light in random scattering media. The surpris... more We investigate the survival of circularly polarized light in random scattering media. The surprising persistence of this form of polarization has a known dependence on the size and refractive index of scattering particles, however a general description regarding polydisperse media is lacking. Through analysis of Mie theory, we present a means of calculating the magnitude of circular polarization memory in complex media, with total generality in the distribution of particle sizes and refractive indices. Quantification of this memory effect enables an alternate pathway toward recovering particle size distribution, based on measurements of diffusing circularly polarized light.

Diagnostic Optical Spectroscopy in Biomedicine II, 2003

ABSTRACT

Saratov Fall Meeting 2010: Optical Technologies in Biophysics and Medicine XII, 2010

ABSTRACT

5th International Conference on Laser Applications in Life Sciences, 1995

ABSTRACT