A dual mechanism for low‐stress hemolysis in laminar blood flow

Abstract

Human blood is sheared in cone-and-plate and parallel-plate rotational vis-R. L. BEISSINGER and cometers, the latter with variable plate spacings h. Plasma is analyzed for hemoglobin and LDH content before and after shearing to determine the extent of M. C. WILLIAMS shear-induced blood damage within the low-stress regime (stress -< 13 Pa). Ceometrical variations in the test apparatus can be accommodated by correlating blood damage with the radially-averaged shear rate. Data on expired blood are shown to imply that much of the damage arises in the bulk fluid, with a smaller contribution from surface effects. Models are proposed to explain these results, obtained over a shear rate range to 5,000 s-I; parallel-plate platen separation is 0.25 < h < 1.00 mm, cone-and-plate angle is 0.5", and both systems have platens 100 mm in diameter.-C.ormlnndr.nce cwworning ttitr piper m r ) bt. addrrrud to c~t h r r H C \~t l l i~m r or H 1. BriwnKer R I Ikisingrr u prernll) Awxtanl l'rofcw,rof ( Iuinical !ingtnrrrinRst Illinoi5In-'pacing between the parallel plates showed that a weak cfitute ol Tiihnol(g+ ('hicage

Erythrocyte Destruction under Periodically Fluctuating Shear Rate: Comparative Study with Constant Shear Rate

“…Shear rates applied in the present study (<1,000 s-') are chosen in the range of shear rates of blood flow in the human cardiovascular system (12). This range corresponds to lower shear stresses (<lo2 dyn cnC2) than those of previous studies (3,5,(13)(14)(15)(16), in which the higher shear stresses (>lo2 dyn cm-2) were applied within a short time (<lo3 s) (Fig. 6C).…”

“…In the present study, only polymethylmethacrylate has been used because of its transparency and machinability . Another method to evaluate surface interactions is to give variations in surface-to-volume ratio (16). The values of hemolysis ratio independent of + (and surface-to-volume ratio) suggest that the effect of surface interaction on the results of the present study may be minor.…”

Reduction of hemolytic blood damage with dextran

“…Blood is carried outward along the top disk and back in along the bottom disk; this vigorous action prevents cell settling and assures that released hemoglobin is quickly and uniformly distributed. The intradisk fluid mechanics are known (Beissinger and Williams, 1984); shear stress varies radially from zero at the centerline to 13 N / m Z (as computed using a viscosity of 5 mPas) a t the upper disk rim. This low range of shear stress approximates quite well the stresses of the human circulatory system; erythrocyte stresses are far from the high-stress threshold.…”

Low‐stress hemolysis in laminar blood flow: Bulk and surface effects in capillaries

“…Chemical Engineering Department Illinois Institute of Technology Chicago, IL 60616 material effects on How-induced hemolysis. However, it had never been shown until recently (Beissinger and Williams, 1984). that blood damage in one device could be predicted quantitatively from that in another.…”