Potential Point-of-Care Microfluidic Devices to Diagnose Iron Deficiency Anemia

Advances in Microfluidics for Single Red Blood Cell Analysis

The utilizations of microfluidic chips for single RBC (red blood cell) studies have attracted great interests in recent years to filter, trap, analyze, and release single erythrocytes for various applications. Researchers in this field have highlighted the vast potential in developing micro devices for industrial and academia usages, including lab-on-a-chip and organ-on-a-chip systems. This article critically reviews the current state-of-the-art and recent advances of microfluidics for single RBC analyses, including integrated sensors and microfluidic platforms for microscopic/tomographic/spectroscopic single RBC analyses, trapping arrays (including bifurcating channels), dielectrophoretic and agglutination/aggregation studies, as well as clinical implications covering cancer, sepsis, prenatal, and Sickle Cell diseases. Microfluidics based RBC microarrays, sorting/counting and trapping techniques (including acoustic, dielectrophoretic, hydrodynamic, magnetic, and optical techniques) are also reviewed. Lastly, organs on chips, multi-organ chips, and drug discovery involving single RBC are described. The limitations and drawbacks of each technology are addressed and future prospects are discussed.

Efficient and Simple Paper-Based Assay for Plasma Separation Using Universal Anti-H Agglutinating Antibody

BACKGROUND

Conventional laboratory tests require plasma separation using centrifugation by skilled personnel in well-equipped lab. Development of a simple, reliable, and cheap point-of-care (POC) test for plasma separation will overcome these limitations.

METHODS

Plasma separation was achieved in filter paper using the anti-H agglutinating antibody. Hydrophobic channels were created using a solid ink printer. The reproducibility, efficiency, recovery, and applicability of the assay were validated on a large number of blood samples.

RESULTS

A simple, fast, cheap, and direct paper-based assay for plasma separation from whole blood using universal anti-H agglutinating antibody was developed without equipment or pretreatment requirements. The purity of plasma separation using anti-H treated paper was confirmed by microscopy and biuret test for plasma albumin detection. Plasma separation was affected by paper structure, antibody concentration, donor gender, and hematocrit. The efficiency of the assay was 72% and the reproducibility was about 90% with minimal interassay and intra-assay variabilities. The assay successfully separated plasma from 116/119 samples, indicating high sensitivity (97.5%). Furthermore, the assay accurately recovers thyroid stimulating hormone from samples compared to standard methods with 107% recovery rate.

CONCLUSIONS

Paper-based plasma separation using anti-H agglutinating antibodies would have numerous applications in paper-based POC tests and in resource limited areas.

Anemia Diagnostic System Based on Impedance Measurement of Red Blood Cells

Anemia is a condition in which red blood cells or the hemoglobin in the blood is lower than in healthy people. Red blood cells transport and supply oxygen needed to various organs in the human body. Anemia is caused by hypoxemia due to the lack of red blood cells and causes other serious health problems, such as heart problems, pregnancy complications, severe fatigue, or death. There are many causes of anemia, and it can be diagnosed by measuring hematocrit or hemoglobin levels in the blood. Even though there are various diagnostic devices on the market, these devices are inconvenient because their systems are bulky, heavy, expensive, or inaccurate. This study proposed a new anemia diagnostic system based on the impedance measurement of red blood cells. The proposed system consists of a test strip that collects a blood sample from the finger and a hemoglobin meter that measures the impedance of the blood and converts it into the concentration of hemoglobin. The proposed test strip that does not contain enzymes or reagents was designed in accordance with class 1 approval by the Food and Drug Administration (FDA). The hemoglobin meter was designed to include a hardware block, an algorithm block and a calibration block through empirical work. We also compared it to reference impedance to prove the accuracy of the hemoglobin meter. The experimental results with human blood indicated the superiority of the anemia diagnostic system. As a result, the overall standard deviation of impedance measurements was less than 1%, and the coefficient of variance of the proposed system was 1.7%, which was better than that of other commercial systems.

Emerging point-of-care technologies for anemia detection

Anemia, characterized by low blood hemoglobin level, affects about 25% of the world's population with the heaviest burden borne by women and children. Anemia leads to impaired cognitive development in children, as well as high morbidity and early mortality among sufferers. Anemia can be caused by nutritional deficiencies, oncologic treatments and diseases, and infections such as malaria, as well as inherited hemoglobin or red cell disorders. Effective treatments are available for anemia upon early detection and the treatment method is highly dependent on the cause of anemia. There is a need for point-of-care (POC) screening, early diagnosis, and monitoring of anemia, which is currently not widely accessible due to technical challenges and cost, especially in low- and middle-income countries where anemia is most prevalent. This review first introduces the evolution of anemia detection methods followed by their implementation in current commercially available POC anemia diagnostic devices. Then, emerging POC anemia detection technologies leveraging new methods are reviewed. Finally, we highlight the future trends of integrating anemia detection with the diagnosis of relevant underlying disorders to accurately identify specific root causes and to facilitate personalized treatment and care.

Point-of-care technologies in heart, lung, blood and sleep disorders from the Center for Advancing Point-of-Care Technologies

Recent advancements in point-of-care technologies have transformed care for patients with heart, lung, blood, and sleep disorders by providing rapid, cost-effective, and accessible solutions to challenges in the detection and management of many health conditions. However, major barriers exist throughout the technology development process that inhibit the actualization of many promising and potentially successful ideas. The Center for Advancing Point of Care Technologies has established a system for supporting further innovation in this field and bridging the gap between initial idea conception and implementation. We highlight current and emerging point-of-care technologies throughout the development spectrum and emphasize the need for a needs-driven model of health technology development that involve appropriate stakeholders in the process.

Microfluidic system for screening disease based on physical properties of blood

Introduction: A key feature of the 'One Health' concept pertains to the design of novel point of care systems for largescale screening of health of the population residing in resource-limited areas of low- and middle-income countries with a view to obtaining data at a community level as a rationale to achieve better public health outcomes. The physical properties of blood are different for different samples. Our study involved the development of an innovative system architecture based upon the physical properties of blood using automated classifiers to enable large-scale screening of the health of the population living in resource-limited settings. Methods: The proposed system consisted of a simple, robust and low-cost sensor with capabilities to sense and measure even the minute changes in the physical properties of blood samples. In this system, the viscosity of blood was derived from a power-law model coupled with the Rabinowitsch-Mooney correction for non-Newtonian shear rates developed in a steady laminar Poiseuille flow. Surface tension was measured by solving the Young-Laplace equation for pendant drop shape hanging on a vertical needle. An anticipated outcome of this study would be the development of a novel automated classifier based upon the rheological attributes of blood. This automated classifier would have potential application in evaluating the health status of a population at regional and global levels. Results: The proposed system was used to measure the physical properties of various samples like normal, tuberculous and anemic blood samples. The results showed that the physical properties of these samples were different as compared to normal blood samples. The major advantage of this system was low-cost, as well as its simplicity and portability. Conclusion: In this work, we proposed making a case for the validation of a low-cost version of a microfluidic system capable of scanning large populations for a variety of diseases as per the WHO mandate of "One Health".