Evaluation of Hematocrit Measurement Using Spectral Domain Optical Coherence Tomography

Optical coherence tomography (OCT) has the potential to be a noninvasive method for hematocrit (HCT) measurement. This paper studied the effect of erythrocyte aggregation on hematocrit measurement based on monitoring the slope changes in OCT depth reflectivity profile using spectral domain optical coherence tomography (SDOCT). Our measurement indicates that the HCT estimated by SDOCT depends on erythrocyte aggregation state. Measured hematocrit in the blood samples with 2%Dextran500 is underestimated by 17.1-19.5% for HCT from 35- 55% at a flow rate of 4.7 mm/s. The results indicate erythrocyte aggregation is an important factor that will affect accurate hematocrit measurement using SDOCT. Developing methods of simultaneous measurements of BBC aggregation and hematocrit is essential for accurate determination of HCT.