Accurate viscosity measurements of flowing aqueous glucose solutions with suspended scatterers using a dynamic light scattering approach with optical coherence tomography

Abstract

The viscosity of turbid colloidal glucose solutions has been accurately determined from spectral domain optical coherence tomography (OCT) M-mode measurements and our recently developed OCT dynamic light scattering model. Results for various glucose concentrations, flow speeds, and flow angles are reported. The relative "combined standard uncertainty" uc(η) on the viscosity measurements was ±1% for the no-flow case and ±5% for the flow cases, a significant improvement in measurement robustness over previously published reports. The available literature data for the viscosity of pure water and our measurements differ by 1% (stagnant case) and 1.5% (flow cases), demonstrating good accuracy; similar agreement is seen across the measured glucose concentration range when compared to interpolated literature values. The developed technique may contribute toward eventual noninvasive glucose measurements in medicine.

Impact of velocity gradient in Poiseuille flow on the statistics of coherent radiation scattered by flowing Brownian particles in optical coherence tomography

“…For experimental validation, a research-grade fiber-based spectral domain OCT system was used, operating in M-mode for this study. 10 Signals recorded at the photodetector are processed into A-scans, which represent the depth-resolved reflectivity profiles of the sample at a fixed lateral position. M-mode operation was obtained by choosing the signals from the fixed depth of consecutive A-scans (thus as a function of time).…”

“…Blood diffusivity measurements also carry information about blood viscosity, whose increase has been linked to many major cardiovascular risk factors; viscosity may also be modulated by blood glucose levels. 9 Although accurate viscosity measurements are possible in the absence of flow or in a perpendicular measurement geometry, 10 in flowing vessels in many practical situations, this is complicated as the angle between OCT axis and blood flow direction will not be 90 deg and/or maybe unknown. This generates an additional Doppler frequency spread arising from the flow velocity gradient across the OCT detection volume.…”

A Review of Non-Invasive Optical Systems for Continuous Blood Glucose Monitoring

“…The work of [60] investigated the viscosity of turbid colloidal glucose solutions by the spectral domain OCT. In this study, the authors measured the viscosity of aqueous glucose solutions over a range of glucose concentrations.…”

The role of human serum and solution chemistry in fibrinogen peptide–nanoparticle interactions

“…For measurements in glucose solutions, the dispersant refractive index and viscosity were set at 1.35 and 1.1 cP. 63,64 For zeta potential measurements, all samples were made by adding the GF peptide, NPs, and solution additives to a 5 mM sodium phosphate, pH 7.4 (as described in the Reagents and supplies section). All samples had a relatively constant ionic strength except for the samples with 29 mM NaCl, where ionic strength is signicantly higher.…”