title: Comparison of three commercially available ektacytometers with different shearing geometries.
abstract: In December 2008, the International Society for Clinical Hemorheology organized a workshop to evaluate and compare three ektacytometer instruments for measuring deformability of red blood cells (RBC): LORCA (Laser-assisted Optical Rotational Cell Analyzer, RR Mechatronics, Hoorn, The Netherlands), Rheodyn SSD (Myrenne GmbH, Roetgen, Germany) and RheoScan-D (RheoMeditech, Seoul, Korea). Intra-assay reproducibility and biological variation were determined using normal RBC, and cells with reduced deformability (i.e., 0.001-0.02% glutaradehyde (GA), 48 degrees C heat treatment) were employed as either the only RBC present or as a sub-population. Standardized difference values were used as measure of the power to detect differences between normal and treated cells. Salient results include: (1) All instruments had intra-assay variations below 5% for shear stress (SS)>1 Pa but a sharp increase was found for Rheodyn SSD and RheoScan-D at lower SS; (2) Biological variation was similar and markedly increased for SS<3-5 Pa; (3) All instruments detected GA-treated RBC with maximal power at 1-3 Pa, the presence of 10% or 40% GA-modified cells, and the effects of heat treatment. It is concluded that the LORCA, Rheodyn SSD and RheoScan-D all have acceptable precision and power for detecting reduced RBC deformability due to GA treatment or heat treatment, and that the SS range selected for the measurement of deformability is an important determinant of an instrument's power.
authors: Department of Physiology, Akdeniz University, Faculty of Medicine, Antalya, Turkey. baskurt@akdeniz.edu.tr
authors: Oguz K
authors: OK
authors: Baskurt
authors: M R
authors: MR
authors: Hardeman
authors: Mehmet
authors: M
authors: Uyuklu
authors: Pinar
authors: P
authors: Ulker
authors: Melike
authors: M
authors: Cengiz
authors: Norbert
authors: N
authors: Nemeth
authors: Sehyun
authors: S
authors: Shin
authors: Tamas
authors: T
authors: Alexy
authors: Herbert J
authors: HJ
authors: Meiselman
mesh_terms: D000328:Adult; D004867:Equipment Design; D004907:Erythrocyte Deformability / Q000187:drug effects / Q000502:physiology*; D004912:Erythrocytes / Q000187:drug effects; D005976:Glutaral / Q000494:pharmacology; D018056:Hemorheology; D006358:Hot Temperature; D006801:Humans; D007834:Lasers; D008297:Male; D008875:Middle Aged; D015203:Reproducibility of Results; D012212:Rheology / Q000295:instrumentation*; D013314:Stress, Mechanical; D013673:Technology Assessment, Biomedical / Q000379:methods
chemical_list: D005976:Glutaral