Quantitative interpretations of Visible-NIR reflectance spectra of blood

Abstract

This paper illustrates the implementation of a new theoretical model for rapid quantitative analysis of the Vis-NIR diffuse reflectance spectra of blood cultures. This new model is based on the photon diffusion theory and Mie scattering theory that have been formulated to account for multiple scattering populations and absorptive components. This study stresses the significance of the thorough solution of the scattering and absorption problem in order to accurately resolve for optically relevant parameters of blood culture components. With advantages of being calibration-free and computationally fast, the new model has two basic requirements. First, wavelength-dependent refractive indices of the basic chemical constituents of blood culture components are needed. Second, multi-wavelength measurements or at least the measurements of characteristic wavelengths equal to the degrees of freedom, i.e. number of optically relevant parameters, of blood culture system are required. The blood culture analysis model was tested with a large number of diffuse reflectance spectra of blood culture samples characterized by an extensive range of the relevant parameters.

A literature review and novel theoretical approach on the optical properties of whole blood

“…As is acknowledged by various sources [6–8], the assumed scattering phase function of blood in the inverse Monte Carlo analysis highly influences the inferred optical properties—especially μ s and g . Although other measurement methods have been reported for optical property measurements on whole blood [28, 29], we did not encounter any studies that exploit these methods experimentally or the quantitative assessment of spectra of μ a , μ s and g .…”

A new method for the detection of microorganisms in blood cultures: Part I. Theoretical analysis and simulation of blood culture processes

“…Part I of this series reports on the theoretical analysis and computer simulation of the changes in the physical and chemical properties of blood expected as a result of the presence of microorganisms and explores the possibilities of the direct application of spectrophotometric systems for the early detection of pathogens. Part II reports on the quantitative evaluation of multi‐wavelength reflectance spectra of blood (Serebrennikova et al, in preparation). Part III combines the work of Part I and II and applies the quantitative interpretation to experimental blood culture data (Huffman et al, in preparation).…”

“…The physical dimensions of the blood components, primarily the erythrocyte population, have an effect on the optical measurements of blood. The detailed discussion of these effects is the subject of a forthcoming publication (Part II of this series, Serebrennikova et al, in preparation). An example of the physical changes to the erythrocytes can be expressed by the following equation: where V rbc,0 corresponds to the initial or physiological red cell volume, Δ 0 is the maximum volume increase, and k sw is the swelling rate constant in (min −1 ).…”

Non‐invasive Reflectance Spectroscopy for Normal and Cancerous Skin Cells Refractive Index Determination: An In Vitro Study

“…Malignant melanoma comprises about 1% of all skin cancer cases, but causes the vast majority of skin cancer deaths. In 2018, the United States reported approximately 9,320 deaths from melanoma in both sexes .…”