Flow of Physiological Fluids in Microchannels: The Sedimentation Effect

Abstract

ABOUT 6'" WORLD CONGRESS OF BIOMECHANICS The 61h World Congress of Biomechanics is hosled by Biomedical Engineering Sociely of Singapore (BES)logelher wilh lhe Global Enlerprise for Mlcremechanics and Molecular Mediclne (GEM4) and lhe Nalional Unlversily of Singapore (NUS), in conjunclion wilhlhe 141h Inlemalional Conferenee on Biomeehanleal Engineering (ICBME) and lhe 51h Asian Pacine Conlerence on Biomeehanies (APBiomech). Wilh over 2,000 delegales Irom ali over lhe World, espeeially Irem lhe Asia Paeinc region, lo atlend lhis congress, this Biomechanics conference explores a wide fleld such as ergan mechanlcs, tissue mechanlcs, cel! mechanics to molecular mechanics. AI lhe 61h World Congress 01 Biomechanles, aulhors would be presenllng lhe la'!lesl experimental studies, teehnologies and equlpment. Speclal emphasls will be plaeed on slale-of-!he-art teehnology and medicai applleations, lor example in areas 01 sports mediclne and crash injuries.

In Vitro Blood Flow Behaviour in Microchannels with Simple and Complex Geometries

“…Recently Garcia and his colleagues (Garcia et al, 2010(Garcia et al, , 2011 have investigated the flow behaviour of two different physiological fluids frequently used in biomedical microdevices. The working fluids used in this study were physiological saline (PS) and dextran 40 (Dx40) containing about 6% of sheep red blood cells (RBCs), respectively.…”

“…According to our visualization the RBC tend to settle down for period of time superior to 10 minutes. (Garcia et al, 2010(Garcia et al, , 2011.…”

Red blood cell (RBC) suspensions in confined microflows: Pressure-flow relationship

“…As recapitulated in Table 1, the advantages of Dex-40 include preventing aggregation [27] and thus improving microcirculation [28]. Furthermore, the sedimentation of RBCs within tubing occurs at a slow rate [10,11,29], thereby easing the maintenance of experiments, especially when the RBC suspension is stagnant or infused at relatively low flow rates [30]. In contrast to plasma ( μ ∼1.1 cP [31]), the viscosity of Dex-40 is significantly higher with values near ∼4 cP [32] such that Dextran-based suspensions remain non-physiological when compared to in vivo conditions.…”

“…As an alternative (see Table 1), salt-based physiological buffer is an effective choice where phosphate-buffered saline (PBS) is commonly used with a viscosity ( μ = 0.889 cP [33]) much closer to that of plasma. In turn, sedimentation of RBCs suspended in PBS occurs within shorter times compared with Dex-40 [34] where ensuing flow behaviour is acknowledged to be different but has not been thoroughly characterized [29]. One consequence of such property is the necessity to agitate or stir the suspension during experiments [35,36] or frequently mix it to avoid sedimentation [37].…”