Influence of oxygen saturation on the optical scattering properties of human red blood cells in the spectral range 250 to 2000 nm

Abstract

The intrinsic optical parameters absorption coefficient mu(a), scattering coefficient micros, anisotropy factor g, and effective scattering coefficient micros were determined for human red blood cell (RBC) suspensions of hematocrit 33.2% dependent on the oxygen saturation (SAT O(2)) in the wavelength range 250 to 2,000 nm, including the range above 1,100 nm, about which there are no data available in the literature. Integrating sphere measurements of light transmittance and reflectance in combination with inverse Monte Carlo simulation were carried out for SAT O(2) levels of 100 and 0%. In the wavelength range up to 1,200 nm, the absorption behavior is determined by the hemoglobin absorption. The spectral range above the cells' absorption shows no dependence on SAT O(2) and approximates the absorption of water with values 20 to 30% below the respective values for water. Parameters micros and g are significantly influenced by the SAT O(2)-induced absorption changes. Above 600 nm, micros decreases continuously from values of 85 mm(-1) to values of 30 mm(-1) at 2,000 nm. The anisotropy factor shows a slight decrease with wavelengths above 600 nm. In the spectral regions of 1,450 and 1,900 nm where water has local absorption maxima, g shows a significant decrease down to 0.85, whereas micros increases.

Modeling of low coherence interferometry using broadband multi-Gaussian light sources

“…This depends on the tissue type as well as an increase in the longer wavelength and optical power [6]. The axial resolution can be 1 μm to 10 μm depending on the light source spectral shape [7][8]; decreasing in the value with the bandwidth and increasing in the value with the central wavelength [3].…”

Biomedical Image Signal Processing for Reflection-Based Imaging

“…In OCT, a low coherent near infrared source is used to generate a reflection intensity map of the tissues cross section. An OCT scan can be 1 to 3 mm deep (Friebel et al 2009), depending on the tissue type and the optical properties of the light source, specifically the wavelength and intensity. Using a conventional solid state broadband light source, the axial resolution is typically 1 to 10 micrometers, depending on the bandwidth, central wavelength and the sources Fourier envelope shape (Adie 2007) (Rossetti et al 2005) (Shidlovski 2008).…”

Optimizing probe design for an implantable perfusion and oxygenation sensor

“…The first and third layer have the optical properties of liver tissue [23] and the middle layer has the optical properties of whole blood and the dimensions of the vessel under investigation ( Table 1). The optical properties of blood were changed to mimic different oxygenation states [24,25]. Table 2 shows the optical properties of the two oxygenation states of blood at the three wavelengths of interest [25,26].…”