An Approach for Assessing Turbulent Flow Damage to Blood in Medical Devices

Abstract

In this work, contributing factors for red blood cell (RBC) damage in turbulence are investigated by simulating jet flow experiments. Results show that dissipative eddies comparable or smaller in size to the red blood cells cause hemolysis and that hemolysis corresponds to the number and, more importantly, the surface area of eddies that are associated with Kolmogorov length scale (KLS) smaller than about 10 μm. The size distribution of Kolmogorov scale eddies is used to define a turbulent flow extensive property with eddies serving as a means to assess the turbulence effectiveness in damaging cells, and a new hemolysis model is proposed. This empirical model is in agreement with hemolysis results for well-defined systems that exhibit different exposure times and flow conditions, in Couette flow viscometer, capillary tube, and jet flow experiments.

Elongational Stresses and Cells

“…Similarly, Jones found that hemolysis in turbulence corresponded to Kolmogorov length scales comparable to the size to the red blood cell [87]. Such results have been supported with computational work that indicated a direct correlation between the level of hemolysis and the size and persistence of KLS in different turbulent flow fields (jets, Couette viscometers and capillary channels) [7,[88][89][90]. The effects of mechanical trauma are also of interest to other cell types and cell pathologies.…”

Use of Computational Fluid Dynamics to Analyze Blood Flow, Hemolysis and Sublethal Damage to Red Blood Cells in a Bileaflet Artificial Heart Valve

“…At the same flowrate, the malfunctioning valve always had a higher predicted total hemolysis index than the functioning valve. We need to point out here that the model equations, when compared to experiments in the Ozturk et al work [53], yielded a coefficient of determination R 2 between 0.77 and 0.87. Table 6.…”

“…Two new equations (Equations (3) and (4)) have been proposed recently that utilize the surface areas of eddies to predict hemolysis. In these equations, HI is the hemolysis index (% hemolysis); t is the exposure time (in seconds); a, b, c, d and e are coefficients; and EA KLS(D1-D2) is the total surface area of eddies with diameters ranging from D1 to D2 divided by the total volume of the region of interest (in m −1 ) [53]. In Equation (3), the region of interest is composed of all eddies up to 10 µm in diameter, while in Equation (4), it is composed of eddies up to 9 µm in diameter.…”

“…Grid independence analysis for pressure (using the Hutchinson et al run settings[53] with an inlet velocity of 0.445 m/s). The red line on the inset figure indicates the location at which the measurements were taken, with flow from the left towards the right.…”

Modelagem matemática da fluidodinâmica não-newtoniana e bifásica simplificada da hemólise induzida mecanicamente em sistemas de bombeamento centrífugo de sangue

“…Além do conhecimento desses valores limiares, existe uma outra questão importante relacionada à hemólise e que ainda permanece sem resposta: até que nível de trauma mecânico (sub-hemolítico) as hemácias podem suportar sem sofrer prejuízo em seu ciclo de vida normal, isto é, sem que sua vida seja encurtada em decorrência de danos induzidos mecanicamente (Schima e Wieselthaler, 1995), (De Wachter e Verdonck, 2002), (Grigioni et al, 2004), (Heck et al, 2017), (Ozturk et al, 2017).…”