Mr. Andrey A. Bednov Profile

Andrey A. Bednov

at Univ of Texas Medical Branch

SPIE Involvement:

Author

Publications (17)

Proceedings Article | 14 June 2006 Paper

Computer simulation of the processes of inactivation of bacterial cells by dynamic low-coherent speckles

Onega Ulianova, Sergey Ulyanov, Elena Sazanova, Zhang Zhihong, Zhou Sibo, Qingming Luo, Irina Zudina, Andrey Bednov

Proceedings Volume 6254, 62541K (2006) https://doi.org/10.1117/12.679956

KEYWORDS: Oxygen, Molecules, Bacteria, Argon, Molecular interactions, Ions, Computer simulations, Radiation effects, Speckle, Laser therapeutics

Read Abstract +

Proceedings Article | 22 June 2005 Paper

Inactivation of bacterial cells by dynamic low-coherent speckles: mathematical model of photoprocessing

Onega Ulianova, Sergey Ulyanov, Elena Sazanova, Zhihong Zhang, Sibo Zhou, Qingming Luo, Irina Zudina, Andrey Bednov

Proceedings Volume 5771, (2005) https://doi.org/10.1117/12.634847

KEYWORDS: Bacteria, Oxygen, Mathematical modeling, Molecules, Speckle, Computer simulations, Laser processing, Medicine, Microorganisms, Biomedical optics

Read Abstract +

SPIE Journal Paper | 1 March 2004 Open Access

Correlation properties of multiple scattered light: implication to coherent diagnostics of burned skin

Andrey Bednov, Sergey Ulyanov, Cecil Cheung, Arjun Yodh

JBO, Vol. 9, Issue 02, (March 2004) https://doi.org/10.1117/12.10.1117/1.1646171

KEYWORDS: Light scattering, Scattering, Skin, Correlation function, Particles, Blood, Laser scattering, Diagnostics, Tissue optics, Doppler effect

DOWNLOAD PAPER

Proceedings Article | 1 July 2003 Paper

Gluocose monitoring in whole blood by measuring laser-induced acoustic profiles

Andrey Bednov, Elena Savateeva, Alexander Oraevsky

Proceedings Volume 4960, (2003) https://doi.org/10.1117/12.479519

KEYWORDS: Blood, Glucose, Signal attenuation, Tissue optics, Scattering, In vitro testing, In vivo imaging, Optical properties, Tissues, Acoustics

Read Abstract +

Time-resolved optoacoustic (OA) method was employed to measure changes in glucose concentration in the whole and diluted blood. An increase of the glucose level in tissue results in a corresponding decrease of optical scattering. Relative changes in tissue optical scattering can be obtained by measuring the effective optical attenuation coefficient, μ_eff by exponential fitting of the time-resolved optoacoustic profiles. Glucose effects in blood have been investigated using the forward mode of OA detection performed in the visible (at the wavelength, λ=532 nm) and near infrared (λ=1064 nm) spectral ranges. In our previous set of experiments, the OA studies performed in model media in vitro and biological tissue (sclera) in vivo demonstrated gradual reduction of optical scattering with the increase in glucose level. The present study has supported our previous observations. However, one novel effect was observed comprised of a transient increase in μ_eff during the first 5-10 minutes after injection of glucose. This phenomenon may be explained by changes in erythrocytes shape and size as a result of their adaptation to hyperglycemic conditions. Our observation was supported by light microscopy images of red blood cells under normal and hyperglycemic conditions. With glucose concentration changing rapidly (osmotic shock), any small reduction in µeff due to the glucose-induced decrease of relative refraction index of blood, can be compensated or even overwhelmed by the increase in µeff due to erythrocyte shrinkage and/or spherulation. Further cellular adaptation to glucose make erythrocytes return to their normal shape of biconcave disks about 7-μm in diameter. The kinetics of the effective optical attenuation was studies in response to glucose injection in order to better understand the mechanisms of erythrocyte adaptation to osmotic shock and to determine the time course of RBCs adaptation to various glucose concentrations. Finally, Mannitol as alternative osmolyte, which cannot penetrate through the RBC membrane, was used in the study. The effect of Mannitol on optical properties of blood was found to be even more pronounced compared to the effect of glucose. In this study, blood was chosen as an experimental medium with perspective of using the optoacoustic monitoring of glucose concentration either inside veins or in tissues that are well supplied with blood. The results of this study help in designing an optoacoustic measurement protocol for monitoring blood glucose in diabetic patients.

Proceedings Article | 19 May 2000 Paper

Monitoring glucose in vivo by measuring laser-induced acoustic profiles

Andrey Bednov, Alexander Karabutov, Elena Savateeva, Wayne March, Alexander Oraevsky

Proceedings Volume 3916, (2000) https://doi.org/10.1117/12.386317

KEYWORDS: Glucose, Tissues, Sclera, Tissue optics, Scattering, Signal attenuation, In vivo imaging, In vitro testing, Blood, Signal detection

Read Abstract +

The optoacoustic method of monitoring absorbed optical energy distribution in tissues was employed to measure changes in glucose concentration in vivo. Glucose osmotic and hydrophilic properties cause reduction of tissue scattering as a result of glucose concentration increase around scattering particles and fibers. The opto-acoustic (OA) method utilizes time-resolved measurements of laser- induced ultrasonic profile in tissue resembling the distribution of absorbed optical energy. This opto-acoustic profile yields effective optical attenuation coefficient, which decreases with decrease of scattering. Glucose effect has been investigated initially in phantoms resembling optical properties of sclera and polystyrene microspheres water solution colored with potassium chromate and then in sclera in vitro and in sclera of live rabbits. The forward mode of opto-acoustic detection was used in the experiments in vitro. Experiments were performed in UV spectral range at the wavelength of (lambda) equals 355-nm. Experimental results demonstrated that an increase in glucose concentration from 5 mM to 60 mM was expressed in the 3 percent reduction of (mu) _eff in aqueous solution of polystyrene microspheres. The effect of glucose on sclera in vitro was more prominent and measured as 10 percent reduction of (mu) _eff with increase of glucose concentration from 1 mM to 50 mM. It was found that both the amplitude and the profile of OA signal were influenced by mechanical pressure applied to sclera specimen toward the surface of OA transducer. In experiments in live tissue, the backward detection mode was employed, as the only one side access to the tissue surface was available. In experiments in vivo the opto-acoustic profiles were measured in rabbit's sclera before and after intravenous glucose administering. The glucose concentration in rabbit blood was simultaneously measured using commercial device employing chemical analysis of blood. Experimental results demonstrated that a 1 mM increase in glucose concentration resulted in a 3 percent decrease of optical attenuation in rabbit sclera in vivo. Such a pronounced change of optical scattering in sclera in response to physiologic change in blood glucose concentration encourages us to continue measurements in vivo and modeling glucose effect on tissue optics.

Proceedings Article | 28 April 2000 Paper

Coherent diagnostics of burned skin: experiments with phantoms

Andrey Bednov, Cecil Cheng, Sergey Ulyanov, Arjun Yodh

Proceedings Volume 3915, (2000) https://doi.org/10.1117/12.384170

KEYWORDS: Light scattering, Scattering, Skin, Blood, Diagnostics, Blood circulation, Motion models, Particles, Tissue optics, Absorption

Read Abstract +

Proceedings Article | 17 May 1999 Paper

Time-dependent speckle contrast measurements for blood microcirculation monitoring

Dmitry Zimnyakov, Alexey Mishin, Andrey Bednov, Cecil Cheung, Valery Tuchin, Arjun Yodh

Proceedings Volume 3599, (1999) https://doi.org/10.1117/12.348369

KEYWORDS: Speckle, Speckle pattern, Scattering, Multiple scattering, Blood, Light scattering, Statistical analysis, Laser scattering, Sensors, Polarization

Read Abstract +

Proceedings Article | 10 June 1997 Paper

Investigation of lymph flow dynamics using methods of speckle interferometry

Andrey Bednov, Sergey Ulyanov, Valery Tuchin, Gregory Brill, Ekateryna Galanzha

Proceedings Volume 3177, (1997) https://doi.org/10.1117/12.276192

KEYWORDS: Lymphatic system, Blood, Speckle interferometry, Diagnostics, Blood circulation, Nonlinear dynamics, Gaussian beams, Diffraction

Read Abstract +

Proceedings Article | 22 May 1997 Paper

Investigation of statistical properties of lymph-flow dynamics using speckle microscopy

Andrey Bednov, Ekateryna Galanzha, Valery Tuchin, Sergey Ulyanov, Gregory Brill

Proceedings Volume 2981, (1997) https://doi.org/10.1117/12.274311

KEYWORDS: Lymphatic system, Blood, Speckle, Blood circulation, Diffraction, Microscopes, Scattering, Microscopy, Astatine, Diagnostics

Read Abstract +

Proceedings Article | 10 May 1996 Paper

Speckle diagnostics of shuttle-stream lymph and blood flows

Andrey Bednov, Sergey Ulyanov, Valery Tuchin, Gregory Brill, Ekateryna Galanzha

Proceedings Volume 2678, (1996) https://doi.org/10.1117/12.239530

KEYWORDS: Lymphatic system, Blood, Scattering, Diffraction, Blood circulation, Diagnostics, Light scattering, Laser scattering, Gaussian beams, Doppler effect

Read Abstract +

Proceedings Article | 9 February 1996 Paper

In-vivo laser measurements of blood and lymph flow with a small number of scatterers

Andrey Bednov, Sergey Ulyanov, Valery Tuchin, Gregory Brill, E. Zakharova

Proceedings Volume 2732, (1996) https://doi.org/10.1117/12.231684

Read Abstract +

Proceedings Article | 15 January 1996 Paper

Lymph-flow diagnostics using speckle microscopy

Andrey Bednov, Valery Tuchin, Sergey Ulyanov, Gregory Brill, Ekateryna Galanzha

Proceedings Volume 2630, (1996) https://doi.org/10.1117/12.230037

KEYWORDS: Lymphatic system, Diffraction, Diagnostics, Scattering, Speckle, Laser scattering, Microscopes, Microscopy, Gaussian beams, Statistical analysis

Read Abstract +

Proceedings Article | 13 October 1995 Open Access

Practical works in the speckle optics for the subspecialties: physics of laser measurements and biomedical optics

Sergey Ulyanov, Sergey Kuzmin, Andrey Bednov, Valery Tuchin

Proceedings Volume 2525, (1995) https://doi.org/10.1117/12.224057

KEYWORDS: Speckle, Statistical analysis, Physics, Biomedical optics, Diffraction, Laser scattering, Scattering, Profilometers, Gaussian beams, Process modeling

Read Abstract +

DOWNLOAD PAPER

Proceedings Article | 13 October 1995 Open Access

Teaching of optical diffraction methods in biomedicine to undergraduates specializing in optics

Sergey Ulyanov, Valery Tuchin, Sergey Kuzmin, Andrey Bednov

Proceedings Volume 2525, (1995) https://doi.org/10.1117/12.224078

KEYWORDS: Diffraction, Gaussian beams, Biomedical optics, Lymphatic system, Scattering, Laser scattering, Diagnostics, Speckle, Skin, Profilometers

Read Abstract +

DOWNLOAD PAPER

Proceedings Article | 31 January 1995 Paper

Investigation of spatial-temporal correlation functions of dynamic statistically inhomogeneous speckles and their applications in blood flow diagnostics

Sergey Ulyanov, Valery Tuchin, Andrey Bednov

Proceedings Volume 2326, (1995) https://doi.org/10.1117/12.200853

KEYWORDS: Blood, Scattering, Correlation function, Laser scattering, Diffraction, Gaussian beams, Blood circulation, Speckle, Laser optics, Diagnostics

Read Abstract +

Proceedings Article | 2 January 1995 Paper

Blood and lymph flow measurements in microvessels using focused laser beam diffraction phenomenon

Andrey Bednov, Gregory Brill, Valery Tuchin, Sergey Ulyanov, Ekateryna Galanzha

Proceedings Volume 2370, (1995) https://doi.org/10.1117/12.197466

KEYWORDS: Lymphatic system, Diffraction, Blood, Capillaries, Blood circulation, Gaussian beams, Diagnostics, Microscopes, Statistical analysis, Doppler effect

Read Abstract +

Proceedings Article | 10 December 1993 Paper

Investigation of dependence of dynamic partially developed speckle-field contrast on rough-surface statistical characteristics

Andrey Bednov, Sergey Ulyanov

Proceedings Volume 2108, (1993) https://doi.org/10.1117/12.165393

KEYWORDS: Diffraction, Gaussian beams, Speckle, Scattering, Correlation function, Laser scattering, Head, Phase modulation, Convolution, Speckle pattern

Read Abstract +

Showing 5 of 17 publications

View contact details

UPDATE YOUR PROFILE

Is this your profile? Update it now.

Sign into your SPIE.org account

Don’t have a profile and want one?

Create an account on SPIE.org

Keywords/Phrases

Search In:

Publication Years