In vivo investigation of human skin optical clearing and blood microcirculation under the action of glucose solution (original) (raw)
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Optical clearing of skin tissue produced by application of glucose solution: In vivo study
2006
We present experimental results on optical properties ofthe human skin controlled by administration ofthe 40%-glucose solution. In vivo reflectance spectra of the human skin were measured. Results of the experimental study of influence of the 40%-glucose solution on reflectance spectra ofthe human skin are presented. A significant decrease ofreflectance of the human skin under action of the osmotic agent is demonstrated. The experiments show that administration of the glucose solution allows for effective control of tissue optical characteristics, that makes skin more transparent, thereby increasing the ability of light penetration through the tissue. Laser Doppler flowmetry has been used for study of skin blood microcirculation under the action of the glucose solution. Results of the experiments demonstrated that at the action of the glucose solution blood perfusion and blood concentration increase, however the mean blood velocity does not change. The presented results can be used in developing functional imaging techniques, including OCT and reflectance spectroscopy. A potential benefit of the optical clearing technique is the improvement of laser therapeutic techniques that rely on sufficient light penetration to a target embedded in tissue.
Measurement of tissue optical properties in the context of tissue optical clearing
Journal of biomedical optics, 2018
Nowadays, dynamically developing optical (photonic) technologies play an ever-increasing role in medicine. Their adequate and effective implementation in diagnostics, surgery, and therapy needs reliable data on optical properties of human tissues, including skin. This paper presents an overview of recent results on the measurements and control of tissue optical properties. The issues reported comprise a brief review of optical properties of biological tissues and efficacy of optical clearing (OC) method in application to monitoring of diabetic complications and visualization of blood vessels and microcirculation using a number of optical imaging technologies, including spectroscopic, optical coherence tomography, and polarization- and speckle-based ones. Molecular modeling of immersion OC of skin and specific technique of OC of adipose tissue by its heating and photodynamic treatment are also discussed.
SPIE Proceedings, 2001
We present experimental results on optical properties of the rat skin controlled by administration of osmotically active chemical, such as the 40%-glucose solution. In vivo reflectance and in vitro transmittance spectra of the rat skin were measured. Result of the experimental study of influence of the 40%-glucose solution on reflectance and transmittance spectra of the rat skin are presented. The significant increase of transmittance and decrease of reflectance of the rat skin under action of osmotical agent are demonstrated. The average value of glucose solution diffusion coefficient was estimated as 1 .101 .106 0.153. 1O_6 cm2/sec.
Optical Properties of Skin, Subcutaneous, and Muscle Tissues: A Review
The development of optical methods in modern medicine in the areas of diagnostics, therapy, and surgery has stimulated the investigation of optical properties of various biological tissues, since the e±cacy of laser treatment depends on the photon propagation and°uence rate distribution within irradiated tissues. In this work, an overview of published absorption and scattering properties of skin and subcutaneous tissues measured in wide wavelength range is presented. Basic principles of measurements of the tissue optical properties and techniques used for processing of the measured data are outlined.
Saratov Fall Meeting 2000: Optical Technologies in Biophysics and Medicine II, 2001
We present experimental results on optical properties of the rat skin controlled by administration of osmotically active chemical, such as the 40%-glucose solution. In vivo reflectance and in vitro transmittance spectra of the rat skin were measured. Result of the experimental study of influence of the 40%-glucose solution on reflectance and transmittance spectra of the rat skin are presented. The significant increase of transmittance and decrease of reflectance of the rat skin under action of osmotical agent are demonstrated. The average value of glucose solution diffusion coefficient was estimated as 1 .101 .106 0.153 . 1O_6 cm2/sec.
Control of skin optical properties: in vivo and in vitro study
This paper presents results of in vivo and in vitro study of rat skin clearing under action of osmotic active liquid. 40%-glucose solution has been used as an osmotic agent. The degree and time of clearing of different skin samples have been studied in vitro. In vivo administration of the clearing agent has been made by hypodermic injection to exclude the protective action of stratum corneum barrier and influence of the adipose layer, which also reduces rate of the agent diffusion into the tissue. The significant increase of transmittance of the skin samples in vitro and decrease of reflectance of skin in vivo in about an hour after glucose administration were demonstrated. The diffusion coefficients of 40%-glucose solution in the rat skin in vitro have been estimated.
Optical Reflectance and Transmittance of Tissues: Principles and Applications
This paper presents a discussion of diagnostic and dosi-metric optical measurements in medicine and biology. The introduction covers the topics of tissue optical properties, tissue boundary conditions , and invasive versus noninvasive measurements. Clinical applications of therapeutic dosimetry and diagnostic spectroscopy are discussed. The principles of diffuse reflectance and transmittance measurements are presented. Experimental studies illustrate reflectance spectroscopy and steady-state versus time-resolved measurements.
Optics and Spectroscopy, 2011
The purpose of the present study is to determine the optical properties of normal and thermally coagulated chicken liver at 720, 740, 770, 810, 825 and 840 nm wavelengths of laser irradiation. So, we were able to evaluate these optical properties (absorption and scattering coefficients) with ex-vivo study using Kubelka Munk Model (KMM) from the radial dependence of the diffuse reflectance with femtosecond pulsed laser in near IR region. These coefficients were significantly increased with coagulation. The penetration depths of the diffused light have been reported to a maximum value of 8.12 ± 0.36 mm in normal liver and 2.49 ± 0.17 mm in coagulated liver at 840 nm showing increasing behavior towards IR region. The Monte Carlo simulation was used to check the theoretical validation of measured optical properties of the tissue that showed a good match with our experimental results. We believe that these differences in optical properties will be helpful for the understanding arid optimal use of laser applications in medicine and differential diagnosis of tissues by using different optical methods. Especially for the investigation of biological tissue for photodynamic therapy (PDT), the knowledge of the specific optical properties and their thermo-induced changes is important.
Quantitative analysis of dehydration in porcine skin for assessing mechanism of optical clearing
Journal of Biomedical Optics, 2011
Dehydration induced by optical clearing agents (OCAs) can improve tissue optical transmittance; however, current studies merely gave some qualitative descriptions. We develop a model to quantitatively evaluate water content with partial least-squares method based on the measurements of near-infrared reflectance spectroscopy and weight of porcine skin. Furthermore, a commercial spectrometer with an integrating sphere is used to measure the transmittance and reflectance of skin after treatment with different OCAs, and then the water content and optical properties of sample are calculated, respectively. The results show that both the reduced scattering coefficient and dehydration of skin decrease with prolongation of action of OCAs, but the relative change in former is larger than that in latter after a 60-min treatment. The absorption coefficient at 1450 nm decreases completely coincident with dehydration of skin. Further analysis illustrates that the correlation coefficient between the relative changes in the reduced scattering coefficient and dehydration is ∼1 during the 60-min treatment of agents, but there is an extremely significant difference between the two parameters for some OCAs with more hydroxyl groups, especially, glycerol or D-sorbitol, which means that the dehydration is a main mechanism of skin optical clearing, but not the only mechanism.