A microfluidic erythrocyte sedimentation rate analyzer using rouleaux formation kinetics

In vitro analysis of multiple blood flow determinants using red blood cell dynamics under oscillatory flow

“…Following the complete disaggregation, the RBCs start to aggregate in the absence of a shear rate until their complete aggregation at the end of 140 th s. The maximum final transmission levels are obtained at the completion of the aggregation phase. The relative transmission level at the 60 th s is taken as a measure of RBC aggregation, 22 namely the aggregation index (AI) where AI = [V 60th out − V 14th out ]. Fig.…”

“…RBC aggregation is the formation of face-to-face RBC clumps at low shear rates and stasis. 22 This mechanism is reversible and affected by cellular properties (surface charge and deformability), medium properties (viscosity and protein level), and flow properties (shear rate). The shear rate of blood flow in healthy circulation is above 10 s −1 where RBCs do not form aggregates.…”

Self-powered disposable prothrombin time measurement device with an integrated effervescent pump

“…Using this principle, we aimed at measuring the prothrombin time of a whole blood sample travelling in a microfluidic channel. However, blood is a non-Newtonian fluid, and blood viscosity varies for everyone, depending on various hematological and external parameters such as hematocrit, plasma proteins' concentration, erythrocyte aggregation, and temperature [36,38]. Two different whole blood samples might have the same PT value, but this does not necessarily mean that these samples have the same viscosity.…”

“…The determination of average blood viscosity during coagulation is important to understand the interrelation between coagulation dynamics and hemorheological properties [40,41]. The viscosity of blood is affected by shear rate due to two distinct internal mechanisms that yields its non-Newtonian characteristics: erythrocyte aggregation and erythrocyte deformation [38,42,43]. Thus, it is critical to perform the coagulation time measurements at physiologically relevant flow conditions.…”

A New Method for the Measurement of Soft Material Thickness

“…These methods proved themselves in several lab-on-a-chip applications. For example, a micro milled chip is employed in ESR (erythrocyte sedimentation rate) measurement (Isiksacan et al 2017;Isiksacan et al 2018) and laser machined PMMA chip is employed in PT (prothrombin time) measurement . Some of these methods realize microchannel fabrication by machining a bulk PMMA material while some of the fabrication methods require machining of PDMS after the spin coating (Isiksacan et al 2016).…”