title: Dynamic deformation and recovery response of red blood cells to a cyclically reversing shear flow: Effects of frequency of cyclically reversing shear flow and shear stress level.
abstract: Dynamic deformation and recovery responses of red blood cells (RBCs) to a cyclically reversing shear flow generated in a 30-microm clearance, with the peak shear stress of 53, 108, 161, and 274 Pa at the frequency of 1, 2, 3, and 5 Hz, respectively, were studied. The RBCs' time-varying velocity varied after the glass plate velocity without any time lag, whereas the L/W change, where L and W were the major and minor axes of RBCs' ellipsoidal shape, exhibited a rapid increase and gradual decay during the deformation and recovery phase. The time of minimum L/W occurrence lagged behind the zero-velocity time of the glass plate (zero stress), and the delay time normalized to the one-cycle duration remained constant at 8.0%. The elongation of RBCs at zero stress time became larger with the reversing frequency. A simple mechanical model consisting of an elastic linear element during a rapid elongation period and a parallel combination of elements such as a spring and dashpot during the nonlinear recovery phase was suggested. The dynamic response behavior of RBCs under a cyclically reversing shear flow was different from the conventional shape change where a steplike force was applied to and completely released from the RBCs.
authors.affiliation: Department of Artificial Organs, Institute of Biomaterials and Bioengineering, Tokyo Medical and Dental University, Tokyo, Japan.
authors.forename: Nobuo
authors.initials: N
authors.lastname: Watanabe
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Kataoka
authors.forename: Toshitaka
authors.initials: T
authors.lastname: Yasuda
authors.forename: Setsuo
authors.initials: S
authors.lastname: Takatani
mesh_terms: D001783:Blood Flow Velocity / Q000502:physiology*; D001794:Blood Pressure / Q000502:physiology*; D016764:Cell Polarity; D002478:Cells, Cultured; D003198:Computer Simulation; D004548:Elasticity; D004912:Erythrocytes / Q000166:cytology* / Q000502:physiology*; D006244:Hardness; D006801:Humans; D008297:Male; D008955:Models, Cardiovascular; D010507:Periodicity; D010812:Physical Stimulation / Q000379:methods*; D033081:Shear Strength; D013314:Stress, Mechanical