Hemoglobin refractive index with concentration table
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The refractive index of human hemoglobin in the visible range
Article (PDF Available) in Physics in Medicine and Biology 56(13):4013-21 · July 2011 with 1,753 Reads
DOI: 10.1088/0031-9155/56/13/017 · Source: PubMed
Cite this publication
O Zhernovaya
Oleksiy Sydoruk
29.23Imperial College London
Valery Victorovich Tuchin
48.08Saratov State University
Alexandre Douplik
31.48Ryerson University
Abstract
Because the refractive index of hemoglobin in the visible range is sensitive to the hemoglobin concentration, optical investigations of hemoglobin are important for medical diagnostics and treatment. Direct measurements of the refractive index are, however, challenging; few such measurements have previously been reported, especially in a wide wavelength range. We directly measured the refractive index of human deoxygenated and oxygenated hemoglobin for nine wavelengths between 400 and 700 nm for the hemoglobin concentrations up to 140 g l(-1). This paper analyzes the results and suggests a set of model functions to calculate the refractive index depending on the concentration. At all wavelengths, the measured values of the refractive index depended on the concentration linearly. Analyzing the slope of the lines, we determined the specific refraction increments, derived a set of model functions for the refractive index depending on the concentration, and compared our results with those available in the literature. Based on the model functions, we further calculated the refractive index at the physiological concentration within the erythrocytes of 320 g l(-1). The results can be used to calculate the refractive index in the visible range for arbitrary concentrations provided that the refractive indices depend on the concentration linearly.