Analytical model of diffuse reflectance spectrum of skin tissue

Method for Estimating Bilirubin Isomerization Efficiency in Phototherapy to Treat Neonatal Jaundice

“…The tissue concentration of bilirubin can be determined by noninvasive methods by measuring the spectral or the spectral and spatial characteristics of the diffuse refl ection by the tissue [14-16, 21, 22]. The measurements can be made based on both fi ber-optic technology [14][15][16] and contactless measurement systems [21,22]. Analytical solutions of the corresponding forward and inverse problems, proposed in [14,16,21,22], allow us to process the measurement data in real time and with high accuracy.…”

“…As shown in [16], such measurements allow us to reliably determine the total bilirubin concentration in the skin tissue when all the skin parameters affecting the radiation fl ux backscattered by the skin are a priori uncertain. Let us consider the possibility of determining the LR formation rate in the skin tissues of a newborn using data from optical probing of the skin with a fi ber-optic spectrometer.…”

“…Let us consider a model for skin with two homogeneous and planeparallel layers: the epidermis and the dermis [14][15][16]. Obviously in such a medium, the radiation fi eld is horizontally homogeneous, i.e., the radiation density E(z, λ) depends only on the one vertical coordinate z, measured from the surface of the medium.…”

“…An analytical model for the refl ectance spectrum of the skin, measured with a baseline separation between the radiation source and the radiation detector, was proposed in [16]. By refl ectance we mean the ratio r = P/P 0 , where P 0 is the power of the collimated light incident on the medium; P is the power of diffuse radiation leaving the area on the surface of the medium outside the region hit by the incident light.…”

“…The measurements can be made based on both fi ber-optic technology [14][15][16] and contactless measurement systems [21,22]. Analytical solutions of the corresponding forward and inverse problems, proposed in [14,16,21,22], allow us to process the measurement data in real time and with high accuracy. Taking into account the similarity of the absorption spectra for ZZ-bilirubin and ZE-bilirubin [19], the total bilirubin concentration, determined based on the methods indicated above, will correspond to the total concentration of bilirubin photoisomers in tissue (C TB ).…”