Impact of Blood Volume Changes Within the Human Skin on the Diffuse
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10063-36 Impact of blood volume changes within the human skin on the diffuse reflectance measurements in visible and NIR spectral ranges Evgeny Zherebtsov1,3, Alexander Bykov1, Alexey Popov1, Alexander Doronin2, and Igor Meglinski1 H' 1Opto-Electronics and Measurement Techniques, Faculty of Information Technology and Electrical Engineering, University of Oulu , Erkki Koiso- Kanttilankatu 3, Oulu, 90570, Finland 2Computer Graphics Group, Department of Computer Science, Yale, University, New Haven, CT 06520, USA 3Biomedical Photonics Instrumentation Group, Scientific-Educational Center “Biomedical Engineering”, Oryol State University, Komsomolskaya b. UNIVERSITY 95, Oryol, 302026, Russia OF OULU INTRODUCTION METHODS RESULTS Log I I At present, measurements of diffuse light reflectance Saturation pulsation was modeled by alteration of saturation 10 max from different biological tissues in vivo and in vitro are in the range of 85%–95%. Modulation of the blood volume widely employed as a measurement procedure. The fraction, as well as blood saturation, were completed using recording of the diffuse reflectance is used in such the photoplethysmography function (Fig. 2). diagnostical technologies as steady-state diffuse 25 100 se, l 20 u 95 reflectance spectroscopy, diffusing-wave spectroscopy, p on, g ti Papillary dermis n i 90 a) 545 nm b) 560 nm rac 15 f diffuse correlation spectroscopy, pulse oximetry etc [1,2]. ur Upper blood net dermis d Log I I 85 Log10 I Imax 10 max ume l Reticular dermis on In all cases of using optical measurements to assess 10 i vo 80 d Deep blood net dermis oo parameters of a biological object in vivo and in situ, it is 5 Subcuteneous fat saturat Bl 75 d important to know the actual sampling volume (SV) of the 0 oo Bl 70 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.1 0.2 0.3 0.4 0.5 0.6 0.7 biological tissue. An alteration of the blood volume Time , s Time, s a) b) fraction, as well as oxygen saturation level (in case of Fig. 2 Modeling of alteration of blood volume fraction (a) ii and saturation (b) during pulse measurements beyond of isobestic points of Hb/HbO2 c) 660 nm d) 800 nm The calculations were carried out for the following pair), has strong impact on the geometrical parameters of Fig. 4 Calculated sampling volume of diffuse reflectance sampling volume [3]. wavelengths: 434 nm, 450 nm, 480 nm, 500 nm, 545 nm, measurements for the modelled optical probe for several 560 nm, 660 nm, 800 nm. wavelengths green, yellow, red and NIR optical ranges Theaimofthisworkwastostudytheeffectof 30 sampling volume pulsation of diffuse reflectance 25 RESULTS 434 nm measurements, which arises because of blood The results of modelling of the sampling volume for the 20 450 nm volume fraction pulsation as well as pulsation of 480 nm plane perpendicular to the line connecting the centers of the 15 V, 500 nm blood saturation. S receiving and transmitting fiber are presented in Fig. 3,4. 545 nm 10 560 nm METHODS The mean calculated sampling volumes for different 5 660 nm In this study, the diffuse reflectance measurements of the wavelengths of probing radiation are presented in Tab. 1. 800 nm 0 QR400-7SR (Ocean Optics, Inc) probe sampling volume Relative increment of the pulsatile calculated sampling 0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 t, s were modelled and analyzed. The probe has 6 emitting volume for different wavelength during on pulse period are Fig. 5 Relative increment of calculated sampling volume for fibers and one collecting fiber (Fig. 1). presented in Fig. 5. different wavelengths during on pulse period A CUDA-based Monte-Carlo distributed computing platform Table 1 Mean calculated sampling volume CONCLUSIONS was used for routine simulation of SV and skin reflectance λ, nm 434 450 480 500 545 560 660 800 SV, mm3 0.37 0.77 0.48 1.80 1.05 1.30 28.0 18.5 spectra, as well as their variations associated with We have considered changes in the volume of blood Log10 I Imax Log10 I Imax physiological changes in the human skin [4,5,6]. and oxygen saturation caused by a pulse wave and 480 um 480 um 6,35 mm 400 um their influence on the diffuse reflectance spectra in the '- visible/NIR spectral range. A CUDA-based Monte-Carlo 400 um 400 um model was used for routine simulation of detector depth sensitivity (sampling volume) and skin spectra, and o o 25 25o 25 LI a) 434 nm b) 450 nm their variations associated with physiological changes Log I I in the human skin. The results are of particular interest Fig. 1 The schema of measurements a human skin by the Log10 I Imax 10 max probe QR400-7SR (Ocean Optics, Inc) for pulse oximetry, photoplethysmography, Doppler In the used model, the absorption coefficients of each layer flowmetry, reflectance spectroscopy. take into account the concentration of blood C in various blood REFERENCES vascular beds, oxygen saturation S, water content CH2O and 1. A.V. Dunaev et al, JBO 18(10), 4. Doronin, I. Meglinski, Biomed. Opt. 107009 (2013). Express, 2(9), 2461-2469 (2011). melanin fraction Cmel as it is defined in [5,6]. c) 480 nm d) 500 nm 2. A.V. Dunaev et al, Med Eng Phys. 5. G.I. Petrov et al., Biomed. Opt. Express, Blood pulsation was modelled by relative alteration of blood 37(6), 574-583 (2015). 3(9), 2154-2161 (2012). Fig. 3 Calculated sampling volume of diffuse reflectance 3. I. Meglinski et al, Med. Biol. Eng. 6. I. Meglinski et al, Computational Biophysics volume fraction of each skin layer the range of 85% – 100%. measurements for the modelled optical probe for several Comput., 39, 44–50 (2001). of the Skin, Ed. B. Querleux, Singapore, wavelengths of blue optical range Chapter 2 (2014). University of Oulu, Optoelectronics and measurement techniques laboratory – www.biophotonics.fi Dynamics and Fluctuations in Biomedical Photonics XIV, edited by Valery V. Tuchin, Kirill V. Larin, Martin J. Leahy, Ruikang K. Wang, Proc. of SPIE Vol. 10063, 1006312 · © 2017 SPIE CCC code: 1605-7422/17/$18 · doi: 10.1117/12.2250855 Proc. of SPIE Vol. 10063 1006312-1 Downloaded From: http://proceedings.spiedigitallibrary.org/pdfaccess.ashx?url=/data/conferences/spiep/91834/ on 04/02/2017 Terms of Use: http://spiedigitallibrary.org/ss/termsofuse.aspx 1.