Systems for real-time optical diagnostics of biological objects

Lisenko, S. A.; Kugeiko, M. M.; Hotra, O.; Surtel, Wojciech

doi:10.1117/12.2070166

Cited by 2 publications

(4 citation statements)

References 12 publications

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“…When describing the subsurface radiation transfer in scattering media, it is desirable to simplify the solution of the linearised Boltzmann equation [13,16,[28][29][30] using the angular brightness integrals [11,13]. When considering stationary problems, in the process of simplifying the description, a diffusion approximation is obtained, which makes it possible to describe the radiation brightness at point r in direction → s by the expression [11,16]:…”

Section: Existing Diffusion Approximationsmentioning

confidence: 99%

“…Finding a connection between the microphysical and optical characteristics of scattering media is a difficult task. It requires significant effort and time by specialists to calculate radiation patterns and simulate scattering processes [27,28]. Due to the wide variety of such substances, their variability, and the need to verify the created mathematical models, their development, in many cases, will not be commercially viable.…”

Section: Introductionmentioning

confidence: 99%

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Possibilities of Diffuse Reflectance Spectroscopy in Determining and Operational Control of the Optical Properties of Finely Dispersed Scattering Media

et al. 2023

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The characteristics of modern portable spectrometers based on photodetector arrays make it possible to create on their basis a new class of devices for operational control of the optical properties of various media. The introduction into the practice of diffuse reflectance spectroscopy with spatial resolution is hampered by the lack of an analysis of the influence of the width of the spectral region used and other sources of measurement uncertainty on the unambiguous determination of the optical properties of finely dispersed scattering materials. This article describes a method of determining the coefficient of local diffuse reflection and calculating the spectral parameters of the reduced scattering and absorption of radiation based on the differences in their shape, which are clearly manifested in a wide range of the spectrum. This allows the reduction in the determination of the desired spectral dependencies to the formation of a residual function that requires varying the values of only two parameters. A method for normalising the recorded spectral dependencies is described, which makes it possible to minimise the influence of the spectral characteristics of the equipment used on the recorded spectral–spatial profiles. Approbation of the method was carried out on examples of processing spectral–spatial diffuse reflection profiles of four samples of finely dispersed scattering structural materials, as well as diffuse reflection profiles of living tissue in the palm thenar region. The sources of uncertainty that affect the uniqueness of the obtained solutions are found, and solutions are proposed to minimise their influence on the desired spectral dependencies. The results obtained indicate the prospects of using the described method for creating equipment for non-destructive control of the optical properties of finely dispersed materials and media, including living tissues and food products.

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Section: Existing Diffusion Approximationsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Possibilities of Diffuse Reflectance Spectroscopy in Determining and Operational Control of the Optical Properties of Finely Dispersed Scattering Media

et al. 2023

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“…Achievements in the development of operational methods for spectrometric control of the composition of various materials and substances allow their implementation in everyday practice [1][2][3][4][5]. New methods of optical diagnostics appear, based both on the theory of radiation transfer in scattering media [6][7][8][9][10][11][12][13][14] and on original methods for determining the necessary parameters, for example, temperature [15] or gas composition [16]. Modern technologies of digital processing of registered signals simplify the use of these methods in different industries, agriculture, medicine, etc.…”

Section: Introductionmentioning

confidence: 99%

“…Therefore, it is necessary to provide sufficiently accurate spectra of diffusely reflected broadband light radiation at different distances ρ k between the points of radiation entrance and registration. Note that with the correct determination of the spectral absorption coefficient of radiation µ a (λ), it is possible to solve further inverse problems to determine the volume concentration C Vm of the main chromophores of a controlled scattering medium with known spectral absorption coefficients µ am (λ) [27]. The noted features of recording the diffuse reflection spectra at different distances ρ k require conducting of the calibration of microspectrometers [28] with the elimination of the nonlinearity of their light characteristics.…”

Section: Introductionmentioning

confidence: 99%

Investigation of the Possibility of Using Microspectrometers Based on CMOS Photodiode Arrays in Small-Sized Devices for Optical Diagnostics

Hotra

Firago

Levkovich

et al. 2022

Sensors

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The article considers the potential applicability of C12880MA and C11708MA Hamamatsu microspectrometers, which are characterized by an extremely compact design, occupying a small volume of several cubic centimeters, in portable spectrometric equipment with spatial resolution for monitoring the optical properties of condensed scattering media. The development of methods for determining the reduced scattering and absorption spectral coefficients of radiation from various scattering materials and products allows us to speak about the possibility of real-time control of the volume concentration of optically active components included in them, for example, fat and water in dairy products. For this, it is necessary to provide sufficiently accurate spectra of diffusely reflected broadband light radiation at different distances between the points of radiation entrance and registration. The aim of the manuscript is to assess the possibility of using the considered microspectrometers in compact devices for optical diagnostics and control of the optical properties of condensed scattering media. The features of the connection diagram of these microspectrometers and the necessary methods for correcting the initially obtained spectral dependencies of diffusive reflection, which will be of interest to developers of spectral diagnostic equipment, are considered in detail. The need to eliminate the influence of the inhomogeneity of dark counts of a CMOS photodiode array is shown. The hardware functions of the C12880MA and C11708MA Hamammatsu microspectrometers, as well as the AvaSpec 2048L fiber-optic spectrometer, were experimentally measured and compared. Methods for correcting the nonlinearity of their reading scales and light characteristics, as well as improving their equivalent spectral resolution using digital Wiener filtering, are described. It is shown that the equivalent spectral resolution of C12880MA and C11708MA microspectrometers can be improved by about 40% when recording smooth spectra, subject to the condition that the resulting side oscillations are small. It is pointed out that in order to reduce the level of side oscillations in the corrected spectra with improved resolution, it is necessary to ensure the smoothness of the original spectra and a good signal-to-noise ratio. A conclusion is made about the possibility of using the considered microspectrometers in portable spectrometric equipment with careful consideration of their characteristics, the features of their switching circuit, and the necessary software.

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Systems for real-time optical diagnostics of biological objects

Cited by 2 publications

References 12 publications

Possibilities of Diffuse Reflectance Spectroscopy in Determining and Operational Control of the Optical Properties of Finely Dispersed Scattering Media

Possibilities of Diffuse Reflectance Spectroscopy in Determining and Operational Control of the Optical Properties of Finely Dispersed Scattering Media

Investigation of the Possibility of Using Microspectrometers Based on CMOS Photodiode Arrays in Small-Sized Devices for Optical Diagnostics

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