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Objectives: Our objectives were to determine the separation characteristics and blood product quality of a gravity‐driven microfiltration blood separation system (HemoClear, The Netherlands). Background: A range of centrifugal blood separation devices, including intraoperative cell salvage devices (cell savers) and apheresis machines, are available to assist in preparing both allogenic and autologous blood products. These devices are expensive to operate and require extensive training. Methods and Materials: Nine whole blood units were collected under standard conditions and analysed for haematological parameters, thromboelastographic properties, platelet morphology and activation, and red blood cell (RBC) deformability and morphology. Three whole blood units were separated by means of the HemoClear device, into a liquid and cellular component. The cellular component was diluted with SAGM and cold stored for 14 days. To simulate cell salvage six whole blood units were diluted with isotonic saline, followed by multiple HemoClear separation rounds. Results: The recovery of both RBCs (100 ± 1.6%) and white blood cells (99 ± 4.5%) after undiluted filtration were very high, while platelet recovery was high (83 ± 3.0%). During the filtration, and cold storage after filtration storage both the non‐deformable RBC fraction and the RBC maximum elongation remained stable. Parameters of thromboelastography indicated that platelets remain functional after filtration and after 7 days of cold storage. In the cell salvage simulation the total protein load in the cellular fraction was reduced by 65 ± 4.1% after one washing round and 84 ± 1.9% after two consecutive washing rounds. Conclusion: The novel blood filter studied effectively separates whole blood into diluted plasma and platelet‐rich RBCs. Moreover, the device effectively washed diluted whole blood, driving over 80% of proteins to the liquid component. [ABSTRACT FROM AUTHOR]

Dynamic and on‐site analysis of serum from human blood is crucial, however, state‐of‐the‐art blood‐assay methods can only collect single or discrete data of physiological analytes; thus, the online reports of the dynamic fluctuation of key analytes remains a great challenge. Here, we propose a novel separation‐sensing membrane by constructing a heterogeneous‐nanostructured architecture, wherein a surface nanoporous layer continuously extracts serum, while the biosensing nanochannels underneath dynamically recognise biotargets, thereby achieving a continuous testing of vital clinical indices as blood is drawn. By precisely controlling the pore structure and nanoshape of biosensing crystals, this membrane achieved accurate and online glucose and lactate monitoring in patients with a variety of medical conditions within 1 min, which is one order of magnitude faster than state‐of‐the‐art techniques. Moreover, various kinds of bio‐recognisers can be introduced into this membrane to accurately detect glutamate, transaminase, and cancer biomarkers. [ABSTRACT FROM AUTHOR]

In this paper, we report on the development of a microfluidic device, which extracts plasma from low‐volume whole blood (10 μL), and is aimed at integration with microfluidic system for micro analytical systems. The device autonomously separates blood cells and transfers the separated plasma by steady rotation. Based on the original autonomous fluidic control theory, we developed the principle of automatic timed injection of pressurizing medium into the separation chamber. This realizes the transferring of separated plasma from blood separation chamber to the other place, after separating blood cells by centrifugal force. Through the demonstration on a polydimethylsiloxane microfluidic device, we confirmed that the automatic plasma extraction was successfully implemented as designed. The efficiency of separation was evaluated on the basis of the concentrations of blood cells in samples before and after extraction, and the rate of blood cell removal was 98.5%. [ABSTRACT FROM AUTHOR]

Experiments are done with separated human blood decelerated at constant rates to determine the maximum deceleration rate while avoiding remixing of the layers, which have different densities and viscosities. The deceleration rate affects both the stability and separation of particles through sedimentation. The velocity at onset of instability for a constant deceleration rate is experimentally determined for a 12‐cm‐diameter disk. Parameters of cell pack thickness, plasma thickness, and total thickness are investigated experimentally, and the only statistically significant parameter to affect stability is rate of deceleration. The data describe a correlation separating regions of stability and instability. To understand stability in decelerating flow of separated blood plasma and cells, the equations of motion are solved for a two‐layer fluid flow with a moving boundary and free surface. Inclusion of non‐Newtonian rheology of blood predicts large discontinuities in the shear rate, which is proposed as the cause of the interfacial instabilities. © 2019 American Institute of Chemical Engineers AIChE J, 65: 1376–1386, 2019 [ABSTRACT FROM AUTHOR]

Blood is the richest source of diagnostic information. The growing interest in point-of-care analytics prompted several attempts to extract plasma from whole blood in simple diagnostic devices. The simplest method of separation is sedimentation. Here we show the first microfluidic system that uses sedimentation to extract plasma from undiluted blood and integrates execution of liquid assays on the extracted material. We present a microfluidic chip that accepts a small sample (27 μL) of whole blood, separates up to 6 μL of plasma, and uses metered volumes of plasma and of reagent (2-chloro-4-nitrophenyl-α-maltotrioside, CNP-G3) for a liquid enzymatic assay. With a custom designed channel, the system separates blood by sedimentation within few minutes of accepting the sample, mixes it with the reagent, and quantifies spectrophotometrically the product of the enzymatic reaction. As a model demonstration, we show a quantitative enzymatic α-amylase assay that is routinely used in diagnosis of pancreas diseases. The paper reports the design and characterization of the microfluidic device and the results of tests on clinically collected blood samples. The results obtained with the microfluidic system compare well to a reference bench-top analyzer. [ABSTRACT FROM AUTHOR]

SUMMARY Background The ErySep system represents an alternative to centrifuge-based whole blood ( WB) separation, using gravity and filtration through hollow-fibres (0·2 µm pore size) to produce red blood cell ( RBC) and plasma components. The aim of this study was to characterise the quality of ErySep RBC and plasma units compared with standard products from WB held overnight. Methods/Materials Two ABO-compatible WB units ( n = 24) were pooled and split to produce matched products. One of the WB units was separated into components using the ErySep system ( ErySep; n = 12), whereas the other units were separated by centrifugation (control; n = 12). RBC units were stored at 2-6 °C and assessed for in vitro quality over 42 days of storage. Plasma was frozen at −30 °C and tested upon thawing. Results Processing WB with the ErySep system took longer than controls. The ErySep RBC units were of an appropriate volume (307 ± 17 mL) and contained sufficient Hb (50 ± 2 g unit−1). ErySep RBC components contained more microparticles relative to controls at expiry. The plasma volume, total protein, coagulation factor activity (fibrinogen, FV, FVIII) and number of microparticles was lower in the ErySep units compared with controls. Conclusion Following overnight hold of WB, the ErySep system was capable of producing RBC components that met specifications. However, the ErySep plasma components did not meet quality specifications. [ABSTRACT FROM AUTHOR]

The aim of this work is to construct a computational fluid dynamics model capable of simulating the transient non-Newtonian process of apheresis. A Lagrangian–Eulerian model has been developed which tracks the blood particles within a two-dimensional flow configuration. Within the Eulerian method, the fluid mass and momentum conservation equations within the separator are solved using the density and the viscosity is calculated from the blood particle concentrations. Subsequently, the displacement of the blood particles is calculated with a Lagrangian method. Hawksley's model for the density of supensions is used in the variable density calculation. The viscosity is calculated with two models based on Vand's rigid particle suspension viscosity concepts, followed by the flow field calculation in the separator. Simulations were performed for various inlet hematocrit values and separator lengths. The simulations are in satisfactory agreement with experimental results reported in literature, indicating a complete separation of plasma and red blood cells (RBCs), as well as nearly complete separation of red blood cells and platelets. No hemolysis was observed in the simulations because the shear rate remained under the critical value of 150 N/m2. [ABSTRACT FROM AUTHOR]

The aim of this study was to assess the separation of whole blood into red cells and plasma by using the Sangofer® device, which is a gravity-fed, hollow-fibre system. The components would then be compared with those produced by the use of more elaborate technical equipment. Ten whole-blood units were leucoreduced by using a WBF2 filter and immediately separated into red cells and plasma by using the Sangofer® blood-separation device. Red cells were stored in additive solution and tested on days 1 and 42. The plasma was assayed for levels of various coagulation factors and for markers of both coagulation and complement activation. The red-cell parameters were similar to those obtained when routine centrifugation methods were used. The filter did not cause haemolysis. Levels of plasma factor VIII and factor XI were lower than those seen in routinely produced leucoreduced plasma units but there was no evidence of activation of the coagulation and complement systems. The Sangofer® device is simple and straightforward to use and eliminates the need for both centrifugation and automated separation steps during the processing of whole blood into red cells and plasma components. Minor changes are required to make the procedure easier to incorporate into routine use. [ABSTRACT FROM AUTHOR]

The aim of this work is to construct a computational fluid dynamics model capable of simulating the quasitransient process of apheresis. To this end a Lagrangian–Eulerian model has been developed which tracks the blood particles within a delineated two-dimensional flow domain. Within the Eulerian method, the fluid flow conservation equations within the separator are solved. Taking the calculated values of the flow field and using a Lagrangian method, the displacement of the blood particles is calculated. Thus, the local blood density within the separator at a given time step is known. Subsequently, the flow field in the separator is recalculated. This process continues until a quasisteady behavior is reached. The simulations show good agreement with experimental results. They shows a complete separation of plasma and red blood cells, as well as nearly complete separation of red blood cells and platelets. The white blood cells build clusters in the low concentrate cell bed. [ABSTRACT FROM AUTHOR]