Year-end Sale % OFF 
Abstract
The correct accounting of laser emitter parameters for improvement of diagnostic authenticity of methods of optical biomedical diagnostic is important problem for applied biophotonic tasks. The purpose of the current research is estimation of influence of energy distribution profile in transversal section of laser beam on light scattering by human skin layers at photometry by ellipsoidal reflectors.Biomedical photometer with ellipsoidal reflectors for investigation of biological tissue specimens in transmitted and reflected light uses laser probing radiation with infinitely thin, Gauss-type and uniform cross-section profile. Distribution of beams with denoted profiles, which consist of 20 million photons with wavelength 632.8 nm, was modeled by using of Monte-Carlo simulation in human skin layers (corneous layer, epidermis, derma and adipose tissue) of various anatomic thickness and with ellipsoidal reflectors with focal parameter equal to 16.875 mm and eccentricity of 0.66.The modeling results represent that illuminance distribution in zones of photometric imaging is significantly influenced by the laser beam cross-section profile for various thickness of corneous layer and epidermis in transmitted and reflected light, and also derma in reflected light. Illuminance distribution for adipose tissue in reflected and transmitted light, and also derma in transmitted light, practically do not depend of laser beam profile for anatomic thicknesses, which are appropriate for human skin on various sections of body.There are represented results of modified Monte-Carlo simulation method for biomedical photometer with ellipsoidal reflectors during biometry of human skin layers. For highly scattered corneous layer and epidermis the illumination of middle and external rings of photometric images changes depending from the laser beam profile for more than 50 % in transmitted and 30 % in reflected light. For weakly scattering skin layers (derma and adipose layer) the influence of profile can be observed only for derma in reflected layer and is equal not more than 15 %.
Highlights
Class of modern optical informational and measurement devices, which applies for noninvasive and low-invasive diagnostic of different indicators, conditions and diseases, use light-emitting diode or laser probing radiation with corresponding characteristics of energy and wavelength
Output parameters of laser radiation source, such as spectral characteristics, divergence of the laser beam, average or continuous power, coherence degree and modes [3], significantly influences the optical properties, which describes the interaction of such radiation with biological media
As a result of modeling, there was received a series of photo-metric images of second focal plane of top and bottom ellipsoids for separate layers of human skin with different thickness (Figure 3) considering the incident laser beam profiles
Summary
Class of modern optical informational and measurement devices, which applies for noninvasive and low-invasive diagnostic of different indicators, conditions and diseases, use light-emitting diode or laser probing radiation with corresponding characteristics of energy and wavelength. Considering that mentioned methods use light, which is reflected and/or transmitted and the main light scattering organ is human skin, the evaluation of influence of its optical properties on the indicators of the registered light is important and actual problem. Significant part of light, reflected by the skin, creates due to backscattering by different skin layers (corneous layer, epidermis, derma and microvascular system). Absorption of scattered light by skin pigments provide quantitative information about concentration of bilirubin, melanin, water, saturation of hemoglobin with oxygen, actual content of different absorbers in tissues and blood, and this form the basis for the number of previously mentioned methods [1, 4]. Significant penetration of visible and near infrared light through the skin inside the human organism, especially in the wavelength range of «therapeutic window» (650–900 nm), is the basis for number of phototherapy methods [5]
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
