Analytical performance evaluation of the scanning capillary tube viscometer for measurement of whole blood viscosity

Background: Whole blood viscosity (WBV) is the resistance of blood flow in blood vessels. Increased WBV may be a cardiovascular risk factor. The proper screening of WBV can help the early detection of cardiovascular disease. We investigated the performance of a new scanning capillary tube viscometer (SCTV) for the measurement of WBV. Methods: We evaluated the total precision of the SCTV for 20. days using three control viscosity materials, and the within-day precision with the whole blood samples of three different individuals. For the linearity evaluation, serial dilutions of a high concentration standard material were used. For the method comparison, the results of the SCTV method were compared to those of Brookfield rotating viscometer on 227 subjects. Results: The SCTV had good within-run and total-run coefficient of variant (CV)s at low-, medium-, and high-concentration samples, at shear rates of 1 and 300s^-1. The within-day CVs with the three human blood samples were 6.3%, 3.7% and 3.8% at a shear rate of 1s^-1, and 3.2%, 3.0% and 4.1% at a shear rate of 300s^-1. The SCTV method showed an excellent linearity in the range of 84.9 to 558.2 milliPoise (mP) and 28.8 to 71.0 mP at shear rates of 1 and 300s^-1, respectively. For the comparison study, the SCTV and the rotating viscometer showed comparable results. Conclusions: The SCTV showed a stable analytical performance, and was comparable with the rotational viscometer. This new SCTV method can be used in the clinical laboratory for various needs.