Wavelength selection in measuring red blood cell aggregation based on light transmittance

Abstract

Abstract. The reversible aggregation of red blood cells (RBC) is of current basic science and clinical interest. Using a flow channel and light transmittance (LT) through RBC suspensions, we have examined the effects of wavelength (500 to 900 nm) on the static and dynamic aspects of RBC aggregation for normal blood and suspensions with reduced or enhanced aggregation; the effects of oxygenation were also explored. Salient observations include: 1. significant effects of wavelength on aggregation parameters reflecting the extent of aggregation (i.e., number of RBC per aggregate); 2. no significant effects of wavelength on parameters reflecting the time course of RBC aggregation; 3. a prominent influence of hemoglobin oxygen saturation on both extent and time-course related aggregation parameters measured at wavelengths less than 700 nm, but only on the time-course at 800 nm; and 4. the power of parameters in detecting a given alteration of RBC aggregation is affected by wavelength, in general being greater at higher wavelengths. It is recommended that light sources with wavelengths around 800 nm be used in instruments for measuring RBC aggregation via LT. C 2011 Society of Photo-Optical Instrumentation Engineers (SPIE).

Retinal and choroidal intravascular spectral‐domain optical coherence tomography

“…The properties of flowing blood have been investigated in vitro using microscopy, scatterometry, absorptiometry, laser diffraction and high-resolution SD-OCT (Schmid-Schoenbein & Wells 1969;Bitbol 1986;Ninomiya et al 1988;Fujii et al 1999;Enejder et al 2003;Friebel et al 2007;Baskurt et al 2009;Cimalla et al 2011;Nam et al 2011;Uyuklu et al 2011). Because the effective particle size is high in stagnant blood, where erythrocytes form aggregates, there are fewer reflecting surfaces in stagnant than in flowing blood.…”

“…Because the effective particle size is high in stagnant blood, where erythrocytes form aggregates, there are fewer reflecting surfaces in stagnant than in flowing blood. Thus, overall reflectivity is low and light transmission is high in stagnant blood (Ninomiya et al 1988;Fujii et al 1999;Enejder et al 2003;Baskurt et al 2009;Cimalla et al 2011;Uyuklu et al 2011). When blood is set in motion in a tube, erythrocyte aggregates dissolve and the erythrocytes assume a non-random spatial orientation, leading to optical anisotropy (variation in optical properties with the direction of observation) and increased backscattering of light at right angles to the direction of flow.…”

Direct monitoring of erythrocytes aggregation under the effect of the low-intensity magnetic field by measuring light transmission at wavelength 800 nm

“…From light transmission and reflectance, many parameters could be extracted to describe the rheological properties of blood including the rate of aggregation and sedimentation [7]. Later on, Oguz K. Baskurt et al used the same technique to monitor erythrocytes aggregation under different light wavelengths to optimize the conditions that give the best investigation of erythrocytes characterizations [21,23]. The wavelength survey was done previously by Oguz K. Baskurt et al and they found the best wavelength used to study light transmission through blood was 800 nm [23].…”

“…Different techniques have been used to monitor erythrocytes aggregation using light transmission, and different parameters were used to describe the aggregation rate and intensity [7,[21][22][23]. Technique established by M.R.…”

A microfluidic erythrocyte sedimentation rate analyzer using rouleaux formation kinetics

“…The analyzer contains a light-emitting diode (VSMG2700, Vishay) in the near-infrared (NIR) band (wavelength = 830 nm) and a photodetector (VEMT4700, Vishay), former at the top and latter at the bottom of the chip, respectively. Using NIR light, the optical transmission of hemoglobin is minimized, and thus higher transmission signal is obtained (Uyuklu et al 2011). For comparison of ESR results Fig.…”